Add Get Quotient And Remainder In One Operation as a Python TIL

Was fetching remote then checking out stale local branch

README.md

@@ -6,14 +6,15 @@ A collection of concise write-ups on small things I learn day to day across a
 variety of languages and technologies. These are things that don't really
 warrant a full blog post. These are things I've picked up by [Learning In
 Public™](https://dev.to/jbranchaud/how-i-built-a-learning-machine-45k9) and
-pairing with smart people at Hashrocket.
+working across different projects via [VisualMode](https://www.visualmode.dev/).
 
 For a steady stream of TILs, [sign up for my newsletter](https://visualmode.kit.com/newsletter).
 
-_1715 TILs and counting..._
+_1789 TILs and counting..._
 
 See some of the other learning resources I work on:
 
+- [The VisualMode Blog](https://visualmode.dev/blog)
 - [Get Started with Vimium](https://egghead.io/courses/get-started-with-vimium~3t5f7)
 - [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
 - [Vim Un-Alphabet](https://www.youtube.com/playlist?list=PL46-cKSxMYYCMpzXo6p0Cof8hJInYgohU)
@@ -29,6 +30,7 @@ If you've learned something here, support my efforts writing daily TILs by
 * [Ansible](#ansible)
 * [Astro](#astro)
 * [AWS](#aws)
+* [Bash](#bash)
 * [Brew](#brew)
 * [Chrome](#chrome)
 * [Claude Code](#claude-code)
@@ -126,11 +128,16 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Turn Off Output Pager For A Command](aws/turn-off-output-pager-for-a-command.md)
 - [Use Specific AWS Profile With CLI](aws/use-specific-aws-profile-with-cli.md)
 
+### Bash
+
+- [Edit The Current Command Prompt](bash/edit-the-current-command-prompt.md)
+
 ### Brew
 
 - [Clean Up Your Brew Installations](brew/clean-up-your-brew-installations.md)
 - [Configure Brew Environment Variables](brew/configure-brew-environment-variables.md)
 - [Export List Of Everything Installed By Brew](brew/export-list-of-everything-installed-by-brew.md)
+- [Install From Nonstandard Brewfile](brew/install-from-nonstandard-brewfile.md)
 - [Install Go Packages In Brewfile](brew/install-go-packages-in-brewfile.md)
 - [List All Services Managed By Brew](brew/list-all-services-managed-by-brew.md)
 
@@ -157,8 +164,11 @@ If you've learned something here, support my efforts writing daily TILs by
 
 ### Claude Code
 
+- [Allow Edits From The Start](claude-code/allow-edits-from-the-start.md)
 - [Monitor Usage Limits From CLI](claude-code/monitor-usage-limits-from-cli.md)
 - [Open Current Prompt In Default Editor](claude-code/open-current-prompt-in-default-editor.md)
+- [Resume Specific Session](claude-code/resume-specific-session.md)
+- [Stash The Current Prompt To Send Another First](claude-code/stash-the-current-prompt-to-send-another-first.md)
 
 ### Clojure
 
@@ -238,6 +248,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Reload The nginx Configuration](devops/reload-the-nginx-configuration.md)
 - [Resolve The Public IP Of A URL](devops/resolve-the-public-ip-of-a-url.md)
 - [Running Out Of inode Space](devops/running-out-of-inode-space.md)
+- [Set, Get, And Unset Env Vars With Dokku](devops/set-get-and-unset-env-vars-with-dokku.md)
 - [Set Up Domain For Hatchbox Rails App](devops/set-up-domain-for-hatchbox-rails-app.md)
 - [SSH Into A Docker Container](devops/ssh-into-a-docker-container.md)
 - [SSL Certificates Can Cover Multiple Domains](devops/ssl-certificates-can-cover-multiple-domains.md)
@@ -348,8 +359,10 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Count Number Of Commits On A Branch](git/count-number-of-commits-on-a-branch.md)
 - [Create A New Branch With Git Switch](git/create-a-new-branch-with-git-switch.md)
 - [Delete All Untracked Files](git/delete-all-untracked-files.md)
+- [Determine Absolute Path Of Top-Level Project Directory](git/determine-absolute-path-of-top-level-project-directory.md)
 - [Determine The Hash Id For A Blob](git/determine-the-hash-id-for-a-blob.md)
 - [Diffing With Patience](git/diffing-with-patience.md)
+- [Display All Git Log Entries In My Local Timezone](git/display-all-git-log-entries-in-my-local-timezone.md)
 - [Dropping Commits With Git Rebase](git/dropping-commits-with-git-rebase.md)
 - [Dry Runs in Git](git/dry-runs-in-git.md)
 - [Exclude A File From A Diff Output](git/exclude-a-file-from-a-diff-output.md)
@@ -393,6 +406,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Move The Latest Commit To A New Branch](git/move-the-latest-commit-to-a-new-branch.md)
 - [Override The Global Git Ignore File](git/override-the-global-git-ignore-file.md)
 - [Pick Specific Changes To Stash](git/pick-specific-changes-to-stash.md)
+- [Programmatically Grab SHA For Head Commit](git/programmatically-grab-sha-for-head-commit.md)
 - [Pulling In Changes During An Interactive Rebase](git/pulling-in-changes-during-an-interactive-rebase.md)
 - [Push To A Branch On Another Remote](git/push-to-a-branch-on-another-remote.md)
 - [Quicker Commit Fixes With The Fixup Flag](git/quicker-commit-fixes-with-the-fixup-flag.md)
@@ -423,6 +437,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Show What Is In A Stash](git/show-what-is-in-a-stash.md)
 - [Single Key Presses in Interactive Mode](git/single-key-presses-in-interactive-mode.md)
 - [Skip A Bad Commit When Bisecting](git/skip-a-bad-commit-when-bisecting.md)
+- [Skip Git Hooks As Needed](git/skip-git-hooks-as-needed.md)
 - [Skip Pre-Commit Hooks](git/skip-pre-commit-hooks.md)
 - [Staging Changes Within Vim](git/staging-changes-within-vim.md)
 - [Staging Stashes Interactively](git/staging-stashes-interactively.md)
@@ -434,6 +449,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Transition A Branch From One Base To Another](git/transition-a-branch-from-one-base-to-another.md)
 - [Turn Off The Output Pager For One Command](git/turn-off-the-output-pager-for-one-command.md)
 - [Two Kinds Of Dotted Range Notation](git/two-kinds-of-dotted-range-notation.md)
+- [Undo Latest Changes Committed To Specific File](git/undo-latest-changes-committed-to-specific-file.md)
 - [Unstage Changes Wih Git Restore](git/unstage-changes-with-git-restore.md)
 - [Untrack A Directory Of Files Without Deleting](git/untrack-a-directory-of-files-without-deleting.md)
 - [Untrack A File Without Deleting It](git/untrack-a-file-without-deleting-it.md)
@@ -449,7 +465,9 @@ If you've learned something here, support my efforts writing daily TILs by
 ### GitHub
 
 - [Access Your GitHub Profile Photo](github/access-your-github-profile-photo.md)
+- [List PRs Awaiting Your Review](github/list-prs-awaiting-your-review.md)
 - [Open A PR To An Unforked Repo](github/open-a-pr-to-an-unforked-repo.md)
+- [Open File To Specific Line In Browser](github/open-file-to-specific-line-in-browser.md)
 - [Target Another Repo When Creating A PR](github/target-another-repo-when-creating-a-pr.md)
 - [Tell gh What The Default Repo Is](github/tell-gh-what-the-default-repo-is.md)
 
@@ -500,6 +518,7 @@ If you've learned something here, support my efforts writing daily TILs by
 
 ### Heroku
 
+- [Check Ruby Version For Production App](heroku/check-ruby-version-for-production-app.md)
 - [Connect To A Database By Color](heroku/connect-to-a-database-by-color.md)
 - [Deploy A Review App To A Different Stack](heroku/deploy-a-review-app-to-a-different-stack.md)
 - [Diagnose Problems In A Heroku Postgres Database](heroku/diagnose-problems-in-a-heroku-postgres-database.md)
@@ -545,6 +564,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Focus The URL Bar](internet/focus-the-url-bar.md)
 - [Get Random Images From Unsplash](internet/get-random-images-from-unsplash.md)
 - [Grab The RSS Feed For A Substack Blog](internet/grab-the-rss-feed-for-a-substack-blog.md)
+- [Hide Overflowing Text For Google Sheets Column](internet/hide-overflowing-text-for-google-sheets-column.md)
 - [Search Tweets By Author](internet/search-tweets-by-author.md)
 - [Show All Pivotal Stories With Blockers](internet/show-all-pivotal-stories-with-blockers.md)
 - [Verify Site Ownership With DNS Record](internet/verify-site-ownership-with-dns-record.md)
@@ -701,6 +721,7 @@ If you've learned something here, support my efforts writing daily TILs by
 
 ### LLM
 
+- [Count Number Of Tokens In A File](llm/count-number-of-tokens-in-a-file.md)
 - [Send cURL To Claude Text Completion API](llm/send-curl-to-claude-text-completion-api.md)
 - [Use The llm CLI With Claude Models](llm/use-the-llm-cli-with-claude-models.md)
 
@@ -713,6 +734,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Capture Screenshot To Clipboard From CLI](mac/capture-screenshot-to-clipboard-from-cli.md)
 - [Check Network Quality Stats From The Command Line](mac/check-network-quality-stats-from-the-command-line.md)
 - [Clean Up Old Homebrew Files](mac/clean-up-old-homebrew-files.md)
+- [Control Which Monitor App Switcher Appears On](mac/control-which-monitor-app-switcher-appears-on.md)
 - [Convert An HEIC Image File To JPG](mac/convert-an-heic-image-file-to-jpg.md)
 - [Default Screenshot Location](mac/default-screenshot-location.md)
 - [Detect How Long A User Has Been Idle](mac/detect-how-long-a-user-has-been-idle.md)
@@ -731,6 +753,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Require Additional JS Libraries In Postman](mac/require-additional-js-libraries-in-postman.md)
 - [Resize App Windows With AppleScript](mac/resize-app-windows-with-applescript.md)
 - [Resizing Both Corners Of A Window](mac/resizing-both-corners-of-a-window.md)
+- [Reveal Location Of File In Finder.app](mac/reveal-location-of-file-in-finder-app.md)
 - [Run A Hardware Check](mac/run-a-hardware-check.md)
 - [Run AppleScript Commands Inline In The Terminal](mac/run-applescript-commands-inline-in-the-terminal.md)
 - [Set A Window To Its Default Zoom Level](mac/set-a-window-to-its-default-zoom-level.md)
@@ -746,9 +769,13 @@ If you've learned something here, support my efforts writing daily TILs by
 
 - [Create Umbrella Task For All Test Tasks](mise/create-umbrella-task-for-all-test-tasks.md)
 - [List The Files Being Loaded By Mise](mise/list-the-files-being-loaded-by-mise.md)
+- [Look In Ruby Version Dotfile](mise/look-in-ruby-version-dotfile.md)
+- [Override Your Project Mise File](mise/override-your-project-mise-file.md)
+- [Pick From Tasks Using Interactive Picker](mise/pick-from-tasks-using-interactive-picker.md)
 - [Preserve Color Output For Task Command](mise/preserve-color-output-for-task-command.md)
 - [Read Existing Dot Env File Into Env Vars](mise/read-existing-dot-env-file-into-env-vars.md)
 - [Run A Command With Specific Tool Version](mise/run-a-command-with-specific-tool-version.md)
+- [Search Through Bin Paths For Tool Locations](mise/search-through-bin-paths-for-tool-locations.md)
 
 ### MongoDB
 
@@ -826,6 +853,7 @@ If you've learned something here, support my efforts writing daily TILs by
 
 ### pnpm
 
+- [Avoid Vulnerabilities In New Package Versions](pnpm/avoid-vulnerabilities-in-new-package-versions.md)
 - [Execute A Command From The Workspace Root](pnpm/execute-a-command-from-the-workspace-root.md)
 - [Install Command Runs For Entire Workspace](pnpm/install-command-runs-for-entire-workspace.md)
 - [List The Installed Version Of A Specific Package](pnpm/list-the-installed-version-of-a-specific-package.md)
@@ -854,6 +882,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Clear The Screen In psql](postgres/clear-the-screen-in-psql.md)
 - [Clear The Screen In psql (2)](postgres/clear-the-screen-in-psql-2.md)
 - [Compute Hashes With pgcrypto](postgres/compute-hashes-with-pgcrypto.md)
+- [Compute Median Instead Of Average](postgres/compute-median-instead-of-average.md)
 - [Compute The Levenshtein Distance Of Two Strings](postgres/compute-the-levenshtein-distance-of-two-strings.md)
 - [Compute The md5 Hash Of A String](postgres/compute-the-md5-hash-of-a-string.md)
 - [Concatenate Strings With A Separator](postgres/concatenate-strings-with-a-separator.md)
@@ -1021,13 +1050,40 @@ If you've learned something here, support my efforts writing daily TILs by
 ### Python
 
 - [Access Instance Variables](python/access-instance-variables.md)
+- [Access Most Recent Return Value In REPL](python/access-most-recent-return-value-in-repl.md)
+- [Access Variables Outside Loop Scope](python/access-variables-outside-loop-scope.md)
+- [Assert Is Only A Development Check](python/assert-is-only-a-development-check.md)
+- [Avoid Modification With Frozen Dataclass](python/avoid-modification-with-frozen-dataclass.md)
 - [Break Debugger On First Line Of Program](python/break-debugger-on-first-line-of-program.md)
+- [Check If Package Is Installed With Pip](python/check-if-package-is-installed-with-pip.md)
+- [Control Passing Of Time In Tests](python/control-passing-of-time-in-tests.md)
 - [Create A Dummy DataFrame In Pandas](python/create-a-dummy-dataframe-in-pandas.md)
+- [Create A Range Of Descending Values](python/create-a-range-of-descending-values.md)
+- [Deduplicate A List Into A Tuple](python/deduplicate-a-list-into-a-tuple.md)
+- [Define Sequence Of Tests With Parametrize Decorator](python/define-sequence-of-tests-with-parametrize-decorator.md)
 - [Dunder Methods](python/dunder-methods.md)
+- [Easy Key-Value Aggregates With defaultdict](python/easy-key-value-aggregates-with-defaultdict.md)
+- [Get Absolute Seconds From `timedelta` Object](python/get-absolute-seconds-from-timedelta-object.md)
+- [Get Quotient And Remainder In One Operation](python/get-quotient-and-remainder-in-one-operation.md)
+- [Install With PIP For Specific Interpreter](python/install-with-pip-for-specific-interpreter.md)
+- [Iterate First N Items From Enumerable](python/iterate-first-n-items-from-enumerable.md)
+- [Iterate Over A Dictionary](python/iterate-over-a-dictionary.md)
+- [Keep A Tally With collections.Counter](python/keep-a-tally-with-collections-counter.md)
+- [Load A File Into The Python REPL](python/load-a-file-into-the-python-repl.md)
+- [Look Inside Pytest tmp_path](python/look-inside-pytest-tmp-path.md)
+- [Make Dataclass Sortable By Specific Field](python/make-dataclass-sortable-by-specific-field.md)
 - [Override The Boolean Context Of A Class](python/override-the-boolean-context-of-a-class.md)
+- [Parse Relative Time To datetime Object](python/parse-relative-time-to-datetime-object.md)
+- [Reclassify Certain Packages As Dev Dependencies](python/reclassify-certain-packages-as-dev-dependencies.md)
+- [Skip Specific Pytest Test Cases](python/skip-specific-pytest-test-cases.md)
+- [Sort A List Of Dataclass Instances](python/sort-a-list-of-dataclass-instances.md)
+- [Sort Normalized Version Of Data](python/sort-normalized-version-of-data.md)
+- [Start The Debugger When A Test Errors](python/start-the-debugger-when-a-test-errors.md)
 - [Store And Access Immutable Data In A Tuple](python/store-and-access-immutable-data-in-a-tuple.md)
 - [Test A Function With Pytest](python/test-a-function-with-pytest.md)
 - [Use pipx To Install End User Apps](python/use-pipx-to-install-end-user-apps.md)
+- [Use `__post_init__` For `dataclass` Validations](python/use-post-init-for-dataclass-validations.md)
+- [Use Verbose Flag To Get More Diff](python/use-verbose-flag-to-get-more-diff.md)
 
 ### Rails
 
@@ -1062,9 +1118,12 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Cast Common Boolean-Like Values To Booleans](rails/cast-common-boolean-like-values-to-booleans.md)
 - [Change The Nullability Of A Column](rails/change-the-nullability-of-a-column.md)
 - [Change The Time Zone Offset Of A DateTime Object](rails/change-the-time-zone-offset-of-a-datetime-object.md)
+- [Check How Database Is Configured](rails/check-how-database-is-configured.md)
 - [Check If ActiveRecord Update Fails](rails/check-if-activerecord-update-fails.md)
 - [Check If Any Records Have A Null Value](rails/check-if-any-records-have-a-null-value.md)
 - [Check Specific Attributes On ActiveRecord Array](rails/check-specific-attributes-on-activerecord-array.md)
+- [Check The Current Named Log Level](rails/check-the-current-named-log-level.md)
+- [Clean Up Memory Hungry Rails Console Processes](rails/clean-up-memory-hungry-rails-console-processes.md)
 - [Code Statistics For An Application](rails/code-statistics-for-an-application.md)
 - [Columns With Default Values Are Nil On Create](rails/columns-with-default-values-are-nil-on-create.md)
 - [Comparing DateTimes Down To Second Precision](rails/comparing-datetimes-down-to-second-precision.md)
@@ -1371,6 +1430,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Defaulting To Frozen String Literals](ruby/defaulting-to-frozen-string-literals.md)
 - [Define A Custom RSpec Matcher](ruby/define-a-custom-rspec-matcher.md)
 - [Define A Method On A Struct](ruby/define-a-method-on-a-struct.md)
+- [Define A Set Of Class Methods](ruby/define-a-set-of-class-methods.md)
 - [Define Multiline Strings With Heredocs](ruby/define-multiline-strings-with-heredocs.md)
 - [Destructure The First Item From An Array](ruby/destructure-the-first-item-from-an-array.md)
 - [Destructuring Arrays In Blocks](ruby/destructuring-arrays-in-blocks.md)
@@ -1391,6 +1451,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [FactoryGirl Sequences](ruby/factory-girl-sequences.md)
 - [Fail](ruby/fail.md)
 - [Fetch Warns About Superseding Block Argument](ruby/fetch-warns-about-superseding-block-argument.md)
+- [Filter By Type](ruby/filter-by-type.md)
 - [Find The Min And Max With A Single Call](ruby/find-the-min-and-max-with-a-single-call.md)
 - [Finding The Source of Ruby Methods](ruby/finding-the-source-of-ruby-methods.md)
 - [Format A Hash Into A String Template](ruby/format-a-hash-into-a-string-template.md)
@@ -1418,6 +1479,8 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Limit Split](ruby/limit-split.md)
 - [List The Running Ruby Version](ruby/list-the-running-ruby-version.md)
 - [Listing Local Variables](ruby/listing-local-variables.md)
+- [Load A Module And Execute A Statement](ruby/load-a-module-and-execute-a-statement.md)
+- [Make A Long String Of Text Readable](ruby/make-a-long-string-of-text-readable.md)
 - [Make An Executable Ruby Script](ruby/make-an-executable-ruby-script.md)
 - [Make Structs Easier To Use With Keyword Initialization](ruby/make-structs-easier-to-use-with-keyword-initialization.md)
 - [Map With Index Over An Array](ruby/map-with-index-over-an-array.md)
@@ -1471,6 +1534,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Single And Double Quoted String Notation](ruby/single-and-double-quoted-string-notation.md)
 - [Skip Specific CVEs When Auditing Your Bundle](ruby/skip-specific-cves-when-auditing-your-bundle.md)
 - [Skip The Front Of An Array With Drop](ruby/skip-the-front-of-an-array-with-drop.md)
+- [Specify Default For Data Definition](ruby/specify-default-for-data-definition.md)
 - [Specify Dependencies For A Rake Task](ruby/specify-dependencies-for-a-rake-task.md)
 - [Specify How Random Array#sample Is](ruby/specify-how-random-array-sample-is.md)
 - [Split A Float Into Its Integer And Decimal](ruby/split-a-float-into-its-integer-and-decimal.md)
@@ -1534,6 +1598,7 @@ If you've learned something here, support my efforts writing daily TILs by
 
 ### Taskfile
 
+- [Add Default Task To List All Tasks](taskfile/add-default-task-to-list-all-tasks.md)
 - [Create Interactive Picker For Set Of Subtasks](taskfile/create-interactive-picker-for-set-of-subtasks.md)
 - [Run A Task If It Meets Criteria](taskfile/run-a-task-if-it-meets-criteria.md)
 
@@ -1558,6 +1623,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Kill Other Connections To A Session](tmux/kill-other-connections-to-a-session.md)
 - [Kill The Current Session](tmux/kill-the-current-session.md)
 - [List All Key Bindings](tmux/list-all-key-bindings.md)
+- [List Processes Running Across All Session](tmux/list-processes-running-across-all-sessions.md)
 - [List Sessions](tmux/list-sessions.md)
 - [Open New Splits To The Current Directory](tmux/open-new-splits-to-the-current-directory.md)
 - [Open New Window With A Specific Directory](tmux/open-new-window-with-a-specific-directory.md)
@@ -1604,7 +1670,9 @@ If you've learned something here, support my efforts writing daily TILs by
 ### Unix
 
 - [All The Environment Variables](unix/all-the-environment-variables.md)
+- [Apply Successive Filters To Lines In Less](unix/apply-successive-filters-to-lines-in-less.md)
 - [Authorize A cURL Request](unix/authorize-a-curl-request.md)
+- [Browse And Search Help Docs](unix/browse-and-search-help-docs.md)
 - [Cat A File With Line Numbers](unix/cat-a-file-with-line-numbers.md)
 - [Cat Files With Color Using Bat](unix/cat-files-with-color-using-bat.md)
 - [Change Default Shell For A User](unix/change-default-shell-for-a-user.md)
@@ -1616,6 +1684,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Check The Current Working Directory](unix/check-the-current-working-directory.md)
 - [Check The Installed OpenSSL Version](unix/check-the-installed-openssl-version.md)
 - [Clear The Screen](unix/clear-the-screen.md)
+- [Combine All My TILs Into A Single File](unix/combine-all-my-tils-into-a-single-file.md)
 - [Command Line Length Limitations](unix/command-line-length-limitations.md)
 - [Compare Two Variables In A Bash Script](unix/compare-two-variables-in-a-bash-script.md)
 - [Configure cd To Behave Like pushd In Zsh](unix/configure-cd-to-behave-like-pushd-in-zsh.md)
@@ -1634,9 +1703,11 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Curling For Headers](unix/curling-for-headers.md)
 - [Curling With Basic Auth Credentials](unix/curling-with-basic-auth-credentials.md)
 - [Determine ipv4 And ipv6 Public IP Addresses](unix/determine-ipv4-and-ipv6-public-ip-addresses.md)
+- [Diff Two Files In Unified Format](unix/diff-two-files-in-unified-format.md)
 - [Different Ways To Generate A v4 UUID](unix/different-ways-to-generate-a-v4-uuid.md)
 - [Display All The Terminal Colors](unix/display-all-the-terminal-colors.md)
 - [Display Free Disk Space](unix/display-free-disk-space.md)
+- [Display Line Numbers While Using Less](unix/display-line-numbers-while-using-less.md)
 - [Display The Contents Of A Directory As A Tree](unix/display-the-contents-of-a-directory-as-a-tree.md)
 - [Do A Dry Run Of An rsync](unix/do-a-dry-run-of-an-rsync.md)
 - [Do Not Overwrite Existing Files](unix/do-not-overwrite-existing-files.md)
@@ -1662,6 +1733,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Fix Previous Command With fc](unix/fix-previous-command-with-fc.md)
 - [Fix Shim Path After asdf Upgrade](unix/fix-shim-path-after-asdf-upgrade.md)
 - [Fix Unlinked Node Binaries With asdf](unix/fix-unlinked-node-binaries-with-asdf.md)
+- [Format And Display Small Amounts Of Columnar Data](unix/format-and-display-small-amounts-of-columnar-data.md)
 - [Forward Multiple Ports Over SSH](unix/forward-multiple-ports-over-ssh.md)
 - [Generate A SAML Key And Certificate Pair](unix/generate-a-saml-key-and-certificate-pair.md)
 - [Generate A Sequence Of Numbered Items](unix/generate-a-sequence-of-numbered-items.md)
@@ -1684,6 +1756,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Ignore A Directory During ripgrep Search](unix/ignore-a-directory-during-ripgrep-search.md)
 - [Ignore The Alias When Running A Command](unix/ignore-the-alias-when-running-a-command.md)
 - [Include Ignore Files In Ripgrep Search](unix/include-ignore-files-in-ripgrep-search.md)
+- [Inspect EXIF Data For An Image File](unix/inspect-exif-data-for-an-image-file.md)
 - [Interactively Browse Available Node Versions](unix/interactively-browse-availabile-node-versions.md)
 - [Interactively Switch asdf Package Versions](unix/interactively-switch-asdf-package-versions.md)
 - [Interpret Cron Schedule From The CLI](unix/interpret-cron-schedule-from-the-cli.md)
@@ -1730,6 +1803,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Rename A Bunch Of Files By Constructing mv Commands](unix/rename-a-bunch-of-files-by-constructing-mv-commands.md)
 - [Repeat Yourself](unix/repeat-yourself.md)
 - [Replace Pattern Across Many Files In A Project](unix/replace-pattern-across-many-files-in-a-project.md)
+- [Reverse Each Line Of A File](unix/reverse-each-line-of-a-file.md)
 - [Run A Command Repeatedly Several Times](unix/run-a-command-repeatedly-several-times.md)
 - [Run A cURL Command Without The Progress Meter](unix/run-a-curl-command-without-the-progress-meter.md)
 - [Safely Edit The Sudoers File With Vim](unix/safely-edit-the-sudoers-file-with-vim.md)
@@ -1745,6 +1819,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Show A File Preview When Searching With FZF](unix/show-a-file-preview-when-searching-with-fzf.md)
 - [Show Disk Usage For The Current Directory](unix/show-disk-usage-for-the-current-directory.md)
 - [Show The Size Of Everything In A Directory](unix/show-the-size-of-everything-in-a-directory.md)
+- [Show Tree View Of Processes And Subprocesses](unix/show-tree-view-of-processes-and-subprocesses.md)
 - [Skip Paging If Output Fits On Screen With Less](unix/skip-paging-if-output-fits-on-screen-with-less.md)
 - [SSH Escape Sequences](unix/ssh-escape-sequences.md)
 - [SSH With Port Forwarding](unix/ssh-with-port-forwarding.md)
@@ -1760,7 +1835,9 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Unrestrict Where ripgrep Searches](unix/unrestrict-where-ripgrep-searches.md)
 - [Update Package Versions Known By asdf Plugin](unix/update-package-versions-known-by-asdf-plugin.md)
 - [Use fzf To Change Directories](unix/use-fzf-to-change-directories.md)
+- [Use Negative Lookbehind Matching With ripgrep](unix/use-negative-lookbehind-matching-with-ripgrep.md)
 - [Use Regex Pattern Matching With Grep](unix/use-regex-pattern-matching-with-grep.md)
+- [Use The Readline Keybindings Anywhere](unix/use-the-readline-keybindings-anywhere.md)
 - [View A Web Page In The Terminal](unix/view-a-web-page-in-the-terminal.md)
 - [View The Source For A Brew Formula](unix/view-the-source-for-a-brew-formula.md)
 - [Watch The Difference](unix/watch-the-difference.md)
@@ -1997,6 +2074,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Toggle Between Stories In Storybook](workflow/toggle-between-stories-in-storybook.md)
 - [Update asdf Plugins With Latest Package Versions](workflow/update-asdf-plugins-with-latest-package-versions.md)
 - [View A Nicely-Formatted CSV In Terminal](workflow/view-a-nicely-formatted-csv-in-terminal.md)
+- [View Nicely Formatted Markdown From Terminal](workflow/view-nicely-formatted-markdown-from-terminal.md)
 - [View The PR For The Current GitHub Branch](workflow/view-the-pr-for-the-current-github-branch.md)
 
 ### XState
@@ -2031,6 +2109,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Add To The Path Via Path Array](zsh/add-to-the-path-via-path-array.md)
 - [Create And Jump Into A Directory](zsh/create-and-jump-into-a-directory.md)
 - [Link A Scalar To An Array](zsh/link-a-scalar-to-an-array.md)
+- [List Available Zle Keybindings](zsh/list-available-zle-keybindings.md)
 - [Use A Space To Exclude Command From History](zsh/use-a-space-to-exclude-command-from-history.md)
 
 ## Usage
@@ -2056,7 +2135,7 @@ I shamelessly stole this idea from
 
 ## License
 
-© 2015-2025 Josh Branchaud
+© 2015-2026 Josh Branchaud
 
 This repository is licensed under the MIT license. See `LICENSE` for
 details.

Taskfile.yml

@@ -32,8 +32,7 @@ tasks:
   notes:sync:
     desc: Sync latest changes from the notes submodule
     cmds:
-      - git submodule update --remote {{.NOTES_DIR}}
+      - cd {{.NOTES_DIR}} && git checkout main && git pull
-      - cd {{.NOTES_DIR}} && git checkout main
     silent: false
 
   notes:open:
@@ -61,11 +60,6 @@ tasks:
     cmds:
       - git status
 
-  notes:pull:
-    desc: Pull latest changes (alias for sync)
-    cmds:
-      - task notes:sync
-
   notes:diff:
     desc: Show uncommitted changes in notes
     dir: '{{.NOTES_DIR}}'

bash/edit-the-current-command-prompt.md

@@ -0,0 +1,18 @@
+# Edit The Current Command Prompt
+
+A neat feature of `bash` is the ability to open whatever the current state of
+the command prompt is into your default editor.
+
+Let's say we have a really long command that we've just tried to run, but it
+failed and we need to make a small change somewhere in the middle. Instead of
+holding the left arrow key for 30 seconds, we can instead hit `CTRL-X CTRL-E`.
+
+This pops us into our `EDITOR` (or maybe `VISUAL`, not sure which). In my case,
+that is `nvim`. I now have access to all the features I'm used to in `nvim` for
+quickly navigating to and editing, searching and replacing, or whatever.
+
+Once I've got the command how I like it, I can save and exit (`:wq`) and the
+updated command will be executed.
+
+This is similar to [the `fc` builtin](unix/fix-previous-command-with-fc.md),
+which also happens to be available for `zsh`.

brew/install-from-nonstandard-brewfile.md

@@ -0,0 +1,25 @@
+# Install From Nonstandard Brewfile
+
+When you want to install the packages listed in the `Brewfile` for your current
+project (or dotfiles), you can run:
+
+```bash
+$ brew bundle
+```
+
+And `brew` knows to look for and use the `Brewfile` in the current directory.
+
+If, however, you are trying to run `brew bundle` for a `Brewfile` located
+somewhere besides the current directory *OR* you want to target a file with a
+non-standard name (like
+[`Brewfile.personal`](https://github.com/jbranchaud/dotfiles/blob/main/Brewfile.personal)),
+then you can use the `--file` flag.
+
+```bash
+$ brew bundle --file Brewfile.personal
+```
+
+This is what I do [here in my `dotfiles`
+repo](https://github.com/jbranchaud/dotfiles/blob/b053f6251cae7ed52f698fc2a2c40ba82c5881b0/installer/mac-setup.sh#L42-L48).
+
+See `man brew` and find the section on `brew bundle` for more details.

claude-code/allow-edits-from-the-start.md

@@ -0,0 +1,35 @@
+# Allow Edits From The Start
+
+A common pattern for me when using Claude Code is that I start it up in a
+project, I prompt it with a question or feature spec, it either comes up with a
+plan or just starts working, and as soon as it is ready to make its first edits
+to a file, it prompts me something like:
+
+```
+ Do you want to make this edit to Taskfile.yml?
+ ❯ 1. Yes
+   2. Yes, allow all edits during this session (shift+tab)
+   3. Type here to tell Claude what to do differently
+```
+
+That's a nice default so that I don't get surprised by Claude Code editing a
+bunch of files.
+
+However, if I'm in a git-backed project and I'm going into a session intending
+to make edits, then I can skip the formalities. I can tell Claude Code when
+starting up the session that edits are allowed.
+
+```sh
+$ claude --permission-mode acceptEdits
+```
+
+When I do this, I'll see the following indicator below the prompt input field:
+
+```
+  ⏵⏵ accept edits on (shift+tab to cycle)
+```
+
+If I've already started `claude` but I forgot to specify that permission mode, I
+can also toggle right into _accept edits_ by hitting `Shift+Tab`.
+
+[source](https://www.youtube.com/watch?v=_IK18goX4X8)

claude-code/resume-specific-session.md

@@ -0,0 +1,22 @@
+# Resume Specific Session
+
+There are a few different ways to resume a [Claude
+Code](https://code.claude.com/docs/en/overview) session.
+
+First, if I have exited a session for the current project and I want to pick
+back up with that most recent one, then I can use `claude --continue`.
+
+If I have had a few recent sessions for the current project and I want to
+remember what they were and pick up where I left off with one of them, then I
+can use `claude --resume` (with no argument). That will open a picker where I
+can browser through a summary of the recent sessions based on their starting
+prompt. The one I pick is the session that will be resumed.
+
+Finally, if I have grabbed a specific session ID (UUID) during the session from
+the `/status` output, then I can reference that value directly.
+
+```sh
+$ claude --resume 92170532-be31-4a91-b2a9-025b8fa78232
+```
+
+See `claude --help` for more details.

claude-code/stash-the-current-prompt-to-send-another-first.md

@@ -0,0 +1,25 @@
+# Stash The Current Prompt To Send Another First
+
+I've been working my way through the current cohort of Matt Pocock's [Claude
+Code for Real
+Engineers](https://www.aihero.dev/cohorts/claude-code-for-real-engineers-2026-04).
+The best part about going through a series of videos like this is being able to
+pick up big and small tips and tricks from another person's workflow.
+
+One of the small things I picked up in an early video is the ability to stash
+the current prompt.
+
+Let's say I've gone to the trouble of writing out a detailed prompt, `@`'ing
+some files, and so forth. Then I realize I need first prompt Claude to do
+something else first. Instead of copy-pasting that prompt into my notes,
+deleting it, issuing a different prompt, and then pasting it back in, I can hit
+`Ctrl-s`.
+
+`Ctrl-s` will _stash_ the current prompt, clearing out the prompt input. I can
+then type in something else. Once I hit enter for that new prompt, it will be
+sent to Claude and the stashed prompt will be immediately populated back into
+the input.
+
+Though `Ctrl-s` is mentioned when you hit `?` from within `claude` session, I
+don't see it documented anywhere in their [Interactive Mode
+reference](https://code.claude.com/docs/en/interactive-mode).

devops/set-get-and-unset-env-vars-with-dokku.md

@@ -0,0 +1,29 @@
+# Set, Get, And Unset Env Vars With Dokku
+
+The `dokku` CLI provides `config` subcommands for managing environment variables
+for the target container.
+
+An env var can be set for an active container with `config:set`:
+
+```bash
+$ dokku config:set app-name JEMALLOC_ENABLED=true MALLOC_CONF="stats_print:true"
+```
+
+Notice I'm able to set multiple env vars at once if needed.
+
+If I ever need to check what an env var is currently set to for one of my app
+containers, I can use `config:get`:
+
+```bash
+$ dokku config:get app-name JEMALLOC_ENABLED
+true
+```
+
+I can always override any value with another `config:set`. However, if I need to
+entirely remove the env var, I can use `config:unset`:
+
+```bash
+$ dokku config:unset app-name MALLOC_CONF
+```
+
+[source](https://dokku.com/docs/configuration/environment-variables/)

git/determine-absolute-path-of-top-level-project-directory.md

@@ -0,0 +1,39 @@
+# Determine Absolute Path Of Top-Level Project Directory
+
+The `git rev-parse` command is a git plumbing command for parsing different
+kinds of things in git into a canonical form that can be used in a deterministic
+way by scripts. I would typically think of using it to work with branch names,
+tags, and other kinds of refs.
+
+There is a handy, sorta off-label use for it in determining the absolute path of
+the root directory for the current git repository. Use the `--show-toplevel`
+flag with no other arguments.
+
+```bash
+❯ git rev-parse --show-toplevel
+/Users/lastword/dev/jbranchaud/til
+```
+
+Here, I am in the local copy of [my TIL repo](https://github.com/jbranchaud/til). This command gives me the absolute
+path of the top-level directory where that `.git` directory resides.
+
+This is useful for scripts that need to orient themselves to the current
+project's top-level directory regardless of what directory they are being
+executed from. This is useful for things like a git hook script or monorepos
+with scripts located in a specific sub-project directory.
+
+Also worth mentioning is the `--show-superproject-working-tree` flag. In my TIL
+repo, I have a private repository included as a submodule. Within that directory
+`--show-toplevel` will produce the absolute path to the submodule. If I instead
+want the absolute path of the _super project_ (in this case TIL), then I can use
+this other flag.
+
+```bash
+❯ git rev-parse --show-toplevel
+/Users/lastword/dev/jbranchaud/til/notes
+
+❯ git rev-parse --show-superproject-working-tree
+/Users/lastword/dev/jbranchaud/til
+```
+
+See `man git-rev-parse` for more details.

git/display-all-git-log-entries-in-my-local-timezone.md

@@ -0,0 +1,30 @@
+# Display All Git Log Entries In My Local Timezone
+
+I tend to work with remote teams distributed across across multiple time zones.
+In that context, it is important to have an awareness of what time zone each
+person is operating in and to communicate clearly around that.
+
+When looking at the output for `git log` on a distributed team, the timestamps
+for each entry can be all over the place. If I want to understand when something
+was committed, I have to look at the time as well as the time zone offset and
+mentally translate it to my own time zone.
+
+There is a `git config` option to alleviate this issue by having `git log`
+convert and display all timestamps into your local time zone.
+
+```bash
+$ git config --global log.date rfc-local
+```
+
+Running that will add this entry to your _global_ git config file:
+
+```
+[log]
+	date = rfc-local
+```
+
+Now the time that was displaying as `Wed Apr 8 20:12:33 2026 -0400` will display
+as `Wed, 8 Apr 2026 19:12:33 -0500`.
+
+This also helps with smoothing out differences from DST and for commits produced
+by AI agents in sandbox environments where the locale is set to UTC.

git/programmatically-grab-sha-for-head-commit.md

@@ -0,0 +1,33 @@
+# Programmatically Grab SHA For Head Commit
+
+When I use `gh browse path/to/some-file.txt`, it opens the browser to that file
+in GitHub. However, it targets the default branch (`main`) by default which is
+not very useful as a permalink because what that file looks like on `main` is
+liable to change.
+
+There is a `--commit` flag you can use to have it instead open to that file at a
+specific commit SHA.
+
+So what SHA do I pass as an argument to that flag?
+
+Often what I would like to grab is a reference to the current version of the
+file which is whatever it looks like for the `HEAD` commit. But `HEAD` is
+another moving target reference. The `git rev-parse` command can translate
+`HEAD` into a specific SHA though.
+
+```bash
+❯ git rev-parse --short HEAD
+3402428
+
+❯ git rev-parse HEAD
+3402428aadc02cfdc9825c8feb593443e72f50cd
+```
+
+Either of those will work. I can use a bash command substitution then to tie it
+all together into a single command:
+
+```bash
+❯ gh browse path/to/some-file.txt --commit=$(git rev-parse --short HEAD)
+```
+
+See `man git-rev-parse` for more details.

git/skip-git-hooks-as-needed.md

@@ -0,0 +1,33 @@
+# Skip Git Hooks As Needed
+
+Projects have Git hooks configured for all sorts of reasons. Most common are
+`pre-commit` hooks which verify certain aspects of the contents of a commit.
+A `pre-commit` hook could check that the tests all pass, that the changes don't
+include any debugging statements, and so forth. There are all kinds of hooks
+though, like `pre-rebase` and `post-checkout`.
+
+These hooks can sometimes get in the way and we may need to skip or disable them
+on a one-off basis.
+
+Several Git commands offer a `--no-verify` flag which can skip running the hook
+associated with that command.
+
+- `git commit --no-verify` (skips `pre-commit` and `commit-msg` hooks)
+- `git push --no-verify` (skips `pre-push` hook)
+- `git merge --no-verify` (skips `pre-merge-commit` hook)
+- `git am --no-verify` (skips `applypatch-msg` and `pre-applypatch` hooks)
+
+If you look in the `.git/hooks` directory, there are several other hooks not
+covered by the above. So, what if I am doing an action like `git checkout` and I
+want to skip the `post-checkout` hook?
+
+I can override the `hooksPath` config for that one command with the `-c` flag.
+
+```sh
+$ git -c core.hooksPath=/dev/null checkout ...
+```
+
+By setting it to `/dev/null`, it will find *no* hooks available, so none will be
+executed for this command.
+
+See `man git-config` for more details on `core.hooksPath`.

git/undo-latest-changes-committed-to-specific-file.md

@@ -0,0 +1,36 @@
+# Undo Latest Changes Committed To Specific File
+
+I'm reviewing the changes I've made in a PR before I request a review from my
+team. There are a scattering of changes in one file that I've changed my mind
+on. Everything else looks good though. So, I need to undo the changes in that
+file before proceeding.
+
+Manually undoing them is going to be clunky. There is a way to do it with `git
+checkout`, but that is one of the ways in which `git-checkout` was overloaded
+leading to the release of `git-restore`.
+
+Let's use `git-restore` instead. By specifying a `--source`, I can tell `git`
+what _ref_ in the commit history that file should be restored to. I'm on a
+short-lived feature branch, so pointing to `main` is good enough.
+
+```bash
+$ git restore --source=main app/models/customer.rb
+```
+
+If I've changed a file at multiple points on this feature branch and I don't
+want to undo all of them, then pointing to `main` is no longer going to work.
+Instead, I can point to the commit right before the current one (`HEAD`) that
+I'm trying to undo.
+
+```bash
+$ git restore --source=HEAD~ app/models/customer.rb
+```
+
+This really isn't much different than the `git-checkout` version, but I still
+find it to be a little clearer.
+
+```bash
+$ git checkout HEAD~ -- app/models/customer.rb
+```
+
+See `man git-restore` for more details.

github/list-prs-awaiting-your-review.md

@@ -0,0 +1,31 @@
+# List PRs Awaiting Your Review
+
+If you work on a software team or steward an open-source project, then there are
+likely some open PRs that you've been tagged to review. I am usually able to
+catch most review requests as they come up either from the GitHub email
+notifications or by keeping an eye on the PRs tab of active projects. Sometimes
+I get consumed by a task and something slips through the cracks.
+
+There are a couple other ways to quickly check if anything is waiting on my
+review.
+
+From the web UI I can visit the following URL which will show all PRs across all
+projects where my review has been requested:
+
+[https://github.com/pulls/review-requested](https://github.com/pulls/review-requested)
+
+The GitHub CLI (`gh`) can do the same and I can do it right from the terminal
+instead of navigating several clicks within GitHub's web UI.
+
+```bash
+$ gh search prs --review-requested=@me --state=open
+```
+
+That too will list PRs across all projects that are open and awaiting my review.
+
+If that one ends up being a little too noisy, you can also use `gh` to _list_
+just PRs for the current project:
+
+```bash
+$ gh pr list --search "review-requested:@me"
+```

github/open-file-to-specific-line-in-browser.md

@@ -0,0 +1,46 @@
+# Open File To Specific Line In Browser
+
+Often one of the best ways to point a teammate to a line of code is to share a
+GitHub link to a specific file and line number. Sometimes even a specific
+commit.
+
+For the longest time I would manually open GitHub, navigate to that file, and so
+forth. The `gh` CLI supports this with the `browse` subcommand and it takes way
+less time if you already have the repo in your local filesystem.
+
+For instance, if I want to point you to line 11 of the `zshrc.local` file in my
+`dotfiles` repo, I can run the following command:
+
+```bash
+$ gh browse zshrc.local:11
+```
+
+That would open a browser tab to
+[https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11](https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11).
+
+If I wanted a range of lines, I could change it from `11` to, say, `11-27`:
+
+```bash
+$ gh browse zshrc.local:11-27
+```
+
+And I would see this in the browser --
+[https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11-L27](https://github.com/jbranchaud/dotfiles/blob/main/zshrc.local?plain=1#L11-L27).
+
+Both of these URLs are pointing to the `main` branch. If I instead want to
+reference a specific commit, I can use the `--commit` flag.
+
+```bash
+$ gh browse zshrc.local:11-27 --commit=f2f9e78d4fc784643f725c88f7a5a7a077e7f261
+```
+
+I grabbed that from the latest commit in `git log`. That opens to
+[https://github.com/jbranchaud/dotfiles/blob/f2f9e78d4fc784643f725c88f7a5a7a077e7f261/zshrc.local?plain=1#L11-L27](https://github.com/jbranchaud/dotfiles/blob/f2f9e78d4fc784643f725c88f7a5a7a077e7f261/zshrc.local?plain=1#L11-L27).
+
+Another way of doing that would be to use `git rev-parse HEAD`:
+
+```bash
+$ gh browse zshrc.local:11-27 --commit=$(git rev-parse HEAD)
+```
+
+See `gh browse --help` for more details.

heroku/check-ruby-version-for-production-app.md

@@ -0,0 +1,32 @@
+# Check Ruby Version For Production App
+
+While deploying a fresh Rails app to Heroku recently, I ran into an issue. The
+`it` block argument wasn't working despite being on Ruby 4.0. Or so I thought.
+
+Running the following command reported the Ruby version of that Heroku server
+instance:
+
+```bash
+❯ heroku run -- ruby --version
+Running ruby --version on ⬢ my-app... up, run.3090
+ruby 3.3.9 (2025-07-24 revision f5c772fc7c) [x86_64-linux]
+```
+
+I was on `3.3.9` which must have been the fallback default at the time.
+
+Though I had set the Ruby version in my `.ruby-version` file, I had neglected to
+specify it in the `Gemfile` as well. Once I added it to the `Gemfile` and
+redeployed, my Heroku server instance was running the expected version of Ruby.
+
+```bash
+❯ heroku run -- ruby --version
+Running ruby --version on ⬢ my-app... up, run.5353
+ruby 4.0.0 (2025-12-25 revision 553f1675f3) +PRISM [x86_64-linux]
+```
+
+Note: because [I have set `HEROKU_ORGANIZATION` and
+`HEROKU_APP`](set-default-team-and-app-for-project.md) in my environment
+(`.envrc`) for the local copy of the app, I don't need to specify those when
+running the `heroku run` command above.
+
+See `heroku run --help` for more details.

internet/hide-overflowing-text-for-google-sheets-column.md

@@ -0,0 +1,12 @@
+# Hide Overflowing Text For Google Sheets Column
+
+I imported a big CSV into a new Google Sheets document. This included a
+"Description" column with many of the descriptions varying between 50 and 80
+characters. The bottom line is that the description column was flowing over the
+top of the columns next to it. Instead of expanding the width of that column as
+far as the largest description, I wanted to hide the _overflow_.
+
+The way to do this in Google Sheets is to highlight the entire column by
+clicking on the column grouping. Then under the _Format_ menu item is a
+_Wrapping_ submenu. The _Clip_ option is what I was looking for because it clips
+the text that gets shown at the edge of the column.

llm/count-number-of-tokens-in-a-file.md

@@ -0,0 +1,26 @@
+# Count Number Of Tokens In A File
+
+Over time you have accumulated a bunch of small directives, corrections, and
+project details in your `CLAUDE.md` or `AGENTS.md` file. The file doesn't seem
+too big, but you are mindful that it is being included in every prompt. How many
+tokens is it eating from the context window?
+
+OpenAI's BPE (Byte Pair Encoding) tokenization library,
+[`tiktoken`](https://github.com/openai/tiktoken), is an open-source Python
+package. If it is installed on our machine, then we can use it as part of the
+following one-liner to check a file:
+
+```bash
+❯ python -c "import tiktoken, sys; print(len(tiktoken.encoding_for_model('gpt-4o').encode(open(sys.argv[1], 'r', encoding='utf-8').read())))" \
+    AGENTS.md
+1018
+```
+
+I ran this against the `AGENTS.md` file in a team project I'm on. It came out to
+1018 tokens. This is a very good approximation based on the tokenizer trained
+for `gpt-4o`. The tokenizers may vary a little from model to model, but the
+differences for our purposes here are going to be negligible.
+
+This one-liner gets the "first" argument to the command, reads it in, and runs
+that string against the tokenizer. The length of the tokenized encoding is then
+printed.

mac/control-which-monitor-app-switcher-appears-on.md

@@ -0,0 +1,21 @@
+# Control Which Monitor App Switcher Appears On
+
+For the most part when I hit `cmd+tab` (and `cmd+shift+tab`) to switch between
+apps, the visual switcher UI (which shows a row of the open apps) appears on my
+main monitor. However, sometimes I will be hitting `cmd+tab` and nothing shows
+up on my main monitor. I look to the right at my side monitor and there is the
+app switcher UI.
+
+Why is it appearing over there all of a sudden?
+
+The reason is that the app switcher UI is anchored to the same screen where the
+doc is located. Though the doc defaults to my main monitor, if I access the doc
+from the side monitor, now it is anchored there.
+
+To switch it back, I just have to make the doc slide up on my main monitor by
+running my mouse down to the bottom of that screen.
+
+The switch up was because I accidentally accessed the doc on my side monitor
+without realizing.
+
+[source](https://superuser.com/a/744680)

mac/reveal-location-of-file-in-finder-app.md

@@ -0,0 +1,20 @@
+# Reveal Location Of File In Finder.app
+
+In the terminal I have the path to an image file. I want to open Finder.app to
+the location of that image file so that I can drag and drop it into a file
+upload area in the browser.
+
+Instead of opening a Finder.app window and navigating directory by directory to
+the location, I can use the `open` command. Using `open` directly with the image
+file will open the image in Preview.app. I want to reveal the directory that the
+image file is in within Finder.app. _Reveal_ is the keyword and the `-R` flag
+does just that.
+
+Here is an example of this that I actually ran when uploading a screenshot that
+went into [this blogmark post](https://still.visualmode.dev/blogmarks/255):
+
+```bash
+$ open -R /Users/lastword/images/tiobe-index-graph-march-2026.png
+```
+
+See `man open` for more details.

mise/create-umbrella-task-for-all-test-tasks.md

@@ -1,8 +1,7 @@
 # Create Umbrella Task For All Test Tasks
 
-When I was first sketching out the [`mise`
+When I was first sketching out the [`mise` tasks](https://mise.jdx.dev/tasks/running-tasks.html) for a Rails app, I added
-tasks](https://mise.jdx.dev/tasks/running-tasks.html) for a Rails app, I added
+the following two tasks. One is for running all the `rspec` tests. The other is
-the following two tasks. One is for running all the `rspec` tests. The Other is
 for running all the `vitest` (JavaScript) tests.
 
 ```toml
@@ -49,5 +48,4 @@ Running `mise run test:all` won't execute its own command, but because it
 depends on all other `test:*` tasks, the tests will get run through those
 dependencies.
 
-This task naming pattern also allows for calling all tests with `mise run
+This task naming pattern also allows for calling all tests with `mise run "test:**"`.
-"test:**"`.

mise/look-in-ruby-version-dotfile.md

@@ -0,0 +1,27 @@
+# Look In Ruby Version Dotfile
+
+Newer versions of [`mise`](https://mise.jdx.dev/dev-tools/) specifically only
+look for tool versions in `mise.toml` as well as the asdf `.tool-versions` file.
+A lot of Ruby projects use the `.ruby-version` file to indicate the Ruby version
+of a project. To continue to use the `.ruby-version` file instead of migrating
+to `mise.toml`, you need to tell `mise` that you prefer to use the idiomatic
+version file.
+
+I added the following line to my
+[`~/.config/mise/config.toml`](https://github.com/jbranchaud/dotfiles/commit/8edeb7a9c53500e89e88b4079cbd1859ebebcbda)
+file:
+
+```toml
+idiomatic_version_file_enable_tools = ["ruby"]
+```
+
+Now, whenever `mise` is looking for the specified Ruby version of a project, it
+will also look for `.ruby-version`.
+
+Here is a [full list of idomatic version files supported by
+`mise`](https://mise.jdx.dev/configuration.html#idiomatic-version-files).
+
+See
+[`idiomatic_version_file_enable_tools`](https://mise.jdx.dev/configuration/settings.html#idiomatic_version_file_enable_tools)
+as well as the [Ruby-specific documentation](https://mise.jdx.dev/lang/ruby.html#ruby-version-and-gemfile-support)
+for more details.

mise/override-your-project-mise-file.md

@@ -0,0 +1,37 @@
+# Override Your Project Mise File
+
+A project I'm working on has a version-controlled `.mise.toml` file in it. Some
+changes were made to that recently that introduce some env vars that conflict
+with my setup. If I make edits to that file, then I have a modified version of
+`.mise.toml` sitting in my Git working copy.
+
+```
+# .mise.toml
+[env]
+CONFIG_SETTING = "project"
+```
+
+Instead, I can rely on the loading precedence rules of `mise` to override those
+project settings with my individual settings. I can do that with the
+`.mise.local.toml` file which is played on top of any `mise` configuration from
+files further down the precedence chain.
+
+```
+# .mise.local.toml
+[env]
+CONFIG_SETTING = "override"
+```
+
+Assuming I have `mise` setup with my shell environment to automatically load in
+these files, I can now check what takes precedence:
+
+```bash
+$ echo $CONFIG_SETTING
+override
+```
+
+Make sure `.mise.local.toml` is included in the `.gitignore` file to avoid
+checking in your personal environment overrides.
+
+To be sure about what files are loaded and in what order, give `mise cfg` a try.
+I discuss that in more detail in [List The Files Being Loaded By Mise](list-the-files-being-loaded-by-mise.md).

mise/pick-from-tasks-using-interactive-picker.md

@@ -0,0 +1,38 @@
+# Pick From Tasks Using Interactive Picker
+
+In [Add Mise Tasks For Common Workflow
+Commands](https://www.visualmode.dev/add-mise-tasks-for-common-workflow-commands),
+I wrote about a set of tasks I added as shortcuts for connecting to the `rails console` in various environments.
+
+```toml
+# mise.toml
+[tasks."console:staging"]
+description = "Open a Rails console on staging"
+run = "ssh -t my-app-staging dokku run my-app rails console"
+
+[tasks."console:prod"]
+description = "Open a Rails console on production"
+run = "ssh -t my-app-prod dokku run my-app rails console"
+```
+
+When a project is configured with multiple `mise` tasks like this, we can invoke
+`mise run` without any specific arguments and it will prompt you with an
+interactive picker. The picker will populate with all the tasks like so:
+
+```bash
+❯ mise run
+Tasks
+Select a task to run
+❯ console:prod     Open a Rails console on production
+  console:staging  Open a Rails console on staging
+/
+esc clear filter • enter confirm
+```
+
+We can navigate between the options with the arrow keys (and if we exit _filter_
+mode by hitting `esc`, then `j/k` also work to move down and up). While in
+_filter_ mode, we can type into the prompt which will filter the list of
+commands down to just the partial matches.
+
+Once we're targeting the task we want to run, we hit `enter` and the task is
+executed.

mise/search-through-bin-paths-for-tool-locations.md

@@ -0,0 +1,29 @@
+# Search Through Bin Paths For Tool Locations
+
+The `mise bin-paths` command will list all the bin paths that are managed by
+`mise`. When you tell `mise` to install a tool, it installs a specific version
+at a location where its binaries can be made accessible on the system path.
+
+While `mise ls` is useful for seeing what is installed by `mise` and at what
+version, the `bin-paths` command can tell you where those tool installations
+with their binaries are located.
+
+Combine this with `grep` or `rg` to narrow down the results to tools by a
+specific name:
+
+```bash
+❯ mise bin-paths | rg 'neovim'
+/Users/lastword/.local/share/mise/installs/npm-neovim/5.4.0/bin
+/Users/lastword/.local/share/mise/installs/pipx-neovim-remote/2.5.1/bin
+/Users/lastword/.local/share/mise/installs/neovim/0.11.6/bin
+```
+
+I can then look in one of these directories to see the one or more binaries that
+they include. For instance, here is what is in the `node` bin path:
+
+```bash
+❯ ls /Users/lastword/.local/share/mise/installs/node/22.22.0/bin
+ ./   ../   claude@   corepack@   node*   npm*   npx@
+```
+
+See `mise bin-paths --help` for more details.

pnpm/avoid-vulnerabilities-in-new-package-versions.md

@@ -0,0 +1,29 @@
+# Avoid Vulnerabilities In New Package Versions
+
+It seems like every week there is a new supply chain attack where malicious code
+is embedded in a popular, widely-used OSS package. This week's is
+[axios](https://www.stepsecurity.io/blog/axios-compromised-on-npm-malicious-versions-drop-remote-access-trojan).
+
+The [`pnpm` package manager](https://pnpm.io/) has a nice feature that helps
+avoid installing these vulnerable package versions in the first place.
+
+> To reduce the risk of installing compromised packages, you can delay the
+> installation of newly published versions. In most cases, malicious releases
+> are discovered and removed from the registry within an hour.
+
+The [`minimumReleaseAge` config option](https://pnpm.io/settings#minimumreleaseage) tells `pnpm` to not install
+a dependency (including transitive ones) until it has been released for at least
+that many minutes.
+
+For instance, if you wanted to set this to 72 hours, then you'd set this option
+to `4320` minutes like so:
+
+```
+$ pnpm config set minimum-release-age 4320 -g
+```
+
+The global flag (`-g`) will set that in your global config location, e.g.
+`$XDG_CONFIG_HOME/pnpm/rc`. You could also add it specifically to your project
+in the `pnpm-workspace.yaml` file.
+
+[source](https://bsky.app/profile/styfle.dev/post/3miekuyeyrs2w)

postgres/compute-median-instead-of-average.md

@@ -0,0 +1,44 @@
+# Compute Median Instead Of Average
+
+One of the first aggregate functions we might use in PostgreSQL, besides `sum`,
+is `avg`.
+
+```sql
+select avg(book_count) as average_books_read
+from (
+  select users.id, count(books.id) as book_count
+  from users
+  left join books
+    on books.user_id = users.id
+  where books.read_in_year = 2025
+  group by users.id
+) as user_book_counts;
+```
+
+This computes the average of the set of values which sums them all up
+and divides by the count. The average (maybe you've heard this also called the
+_mean_) is not always the best way to understand data, especially when there are
+outliers.
+
+Instead, we might want to compute the _median_ value of our set of data. There
+is no easily identifiable `median` aggregate function. Instead, we can use
+`percentile_cont` with a value of `0.5`. This gets us the 50th percentile of our
+set of data which is the definition of the _median_.
+
+```sql
+select percentile_cont(0.5) within group (
+  order by book_count
+) as median_books_read
+from (
+  select users.id, count(books.id) as book_count
+  from users
+  left join books on books.user_id = users.id and books.read_in_year = 2025
+  group by users.id
+) as user_book_counts;
+```
+
+The full syntax for `percentile_cont` is `percentile_cong(precision) within
+group (order by ...)` because this is an aggregiate that has to work with an
+ordered-set of data.
+
+[source](https://www.postgresql.org/docs/current/functions-aggregate.html)

python/access-most-recent-return-value-in-repl.md

@@ -0,0 +1,34 @@
+# Access Most Recent Return Value In REPL
+
+One of my favorite features of Ruby's `irb` and `pry` are that you can use `_`
+to reference the most recent return value. Often as we use an interpreter or
+REPL, we end up with _intermediate_ values. That is, we've execute some kind of
+statement which returned a value and we now want to use that resulting value in
+our next statement. Python also supports `_`.
+
+Let's say I've run a statement that took a while to process, but I forgot to
+assign it to a variable. Instead of re-running the whole thing, I can create a
+variable that references the previous return value using `_`.
+
+```python
+>>> BytePairEncoding.train_bpe(long_text)
+{'merge_rules': [...], 'vocab': {...}}
+>>> result = _
+>>> list(result.keys())
+['merge_rules', 'vocab']
+```
+
+Even if I don't necessarily want to assign it a variable, it can be nice to
+reference the previous value as I continue with what I'm doing:
+
+```python
+>>> result['merge_rules'][0][1]
+256
+>>> result['vocab'][_]
+b'e '
+```
+
+Notice how the value from the first statement gets used as part of a `dict`
+access.
+
+[source](https://docs.python.org/3/tutorial/introduction.html#numbers)

python/access-variables-outside-loop-scope.md

@@ -0,0 +1,44 @@
+# Access Variables Outside Loop Scope
+
+Here is a function that loops over a list to find the first occurrence of a
+falsy value.
+
+```python
+def find_false(self):
+    for item in self.items:
+        item_type = type(item)
+        print(f"Current item: {item} ({item_type})")
+        if not item:
+            break
+
+    print(f"First false item: {item} ({item_type})")
+```
+
+Notice how at the end of the function, outside of the loop, I am able to access
+both `item` (defined in the loop definition) and `item_type` (defined within the
+loop's body).
+
+Both of these variables are defined, by the loop, in _function scope_ and are
+accessible anywhere in the function after they have been defined.
+
+The title of this TIL is a bit of a misnomer because Python doesn't have the
+concept of a _loop scope_. There are two levels of scope in Python --
+module/global scope and function scope.
+
+I spend most of my time writing Ruby which also has _block scope_, so Python's
+simplified two-level scoping took me by surprise.
+
+Though the code sample above is contrived, this function scope assignment can be
+taken advantage of with loop definitions in scenarios where you want to know
+what the last `item` defined was before the loop terminated.
+
+```python
+for submission in submissions:
+    if passes(submission, criteria):
+        break
+else:
+    raise ValueError("No submissions that meet given criteria")
+
+print(f"Submit first passing submission: {submission.id}")
+submit(submission)
+```

python/assert-is-only-a-development-check.md

@@ -0,0 +1,38 @@
+# Assert Is Only A Development Check
+
+The `assert` keyword is used in Python to write a statement that will check some
+assertion and raise an error if it isn't met. This is only meant to be used as a
+check during development because it can be easily optimized out of the code.
+
+```python
+stuff = None
+
+assert stuff, "We need to have some stuff to proceed"
+
+print(f"We have {stuff or 'something'}!")
+```
+
+If I execute this code with `python`, it will raise on that second line of code.
+
+```bash
+❯ python assert_example.py
+Traceback (most recent call last):
+  File "/Users/lastword/dev/jbranchaud/py-vmt/assert_example.py", line 3, in <module>
+    assert stuff, "We need to have some stuff to proceed"
+           ^^^^^
+AssertionError: We need to have some stuff to proceed
+```
+
+This `assert` statement will be stripped out of the compiled bytecode if the
+`-O` (capital o) flag is used. Notice how running the same file with that flag
+does not lead to an `AssertionError`.
+
+```python
+❯ python -O assert_example.py
+We have something!
+```
+
+If I want to make sanity checks for situations that would be caused by a bug in
+the code, an `assert` statement can be a good candidate. However, if I am making
+runtime checks like validating user input, then an `if` statement and raising
+something like a `ValueError` is better.

python/avoid-modification-with-frozen-dataclass.md

@@ -0,0 +1,47 @@
+# Avoid Modification With Frozen Dataclass
+
+The `@dataclass` decorator can be set as _frozen_ to prevent modification of
+values on instances of that `dataclass`.
+
+Without making it frozen, I can easily subvert validations by changing the value
+of attributes after the `__post_init__` validations are called.
+
+```python
+>>> config = BPEConfig(300, []) # passes validations
+>>> config.vocab_size = 22 # this is invalid, wish this was prevented
+```
+
+Here is the updated `@dataclass` declaration with `frozen=True` passed as a
+parameter.
+
+```python
+from dataclasses import dataclass
+from typing import ClassVar
+
+@dataclass(frozen=True)
+class BPEConfig:
+    BASE_VOCAB_SIZE: ClassVar[int] = 256
+
+    vocab_size: int
+    special_tokens: list[str]
+
+    def __post_init__(self):
+        if self.vocab_size < self.BASE_VOCAB_SIZE:
+            msg = f"vocab_size ({self.vocab_size}) must be greater than or equal to BASE_VOCAB_SIZE ({self.BASE_VOCAB_SIZE})"
+            raise ValueError(msg)
+```
+
+Now I am prevented from modifying a scalar value like `vocab_size` after the
+instance has been created.
+
+```python
+>>> config = BPEConfig(300, [])
+>>> config.vocab_size = 22
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+  File "<string>", line 4, in __setattr__
+dataclasses.FrozenInstanceError: cannot assign to field 'vocab_size'
+```
+
+This doesn't prevent you from modifying the contents of attributes that are
+`list` or `dict` types.

python/check-if-package-is-installed-with-pip.md

@@ -0,0 +1,50 @@
+# Check If Package Is Installed With Pip
+
+I recently installed PyTorch, but when I tried using it, I was getting an error
+about `numpy` not being installed. I was kind of surprised by that because I
+thought I would have already had that.
+
+I wanted to check, so I asked with `pip show`:
+
+```bash
+❯ python3 -m pip show numpy
+WARNING: Package(s) not found: numpy
+```
+
+I can even list everything that is installed with `pip` using `pip list` like
+so:
+
+```bash
+❯ python3 -m pip list
+Package            Version   Build
+------------------ --------- -----
+certifi            2026.1.4
+cffi               2.0.0
+charset-normalizer 3.4.4
+click              8.3.1
+commonmark         0.9.1
+cryptography       46.0.3
+docutils           0.22.4
+filelock           3.24.2
+fsspec             2026.2.0
+idna               3.11
+Jinja2             3.1.6
+...
+```
+
+I then installed `numpy` (`python3 -m pip install numpy`) and how I can use `pip
+show` again to confirm that.
+
+```bash
+❯ python3 -m pip show numpy
+Name: numpy
+Version: 2.4.2
+Summary: Fundamental package for array computing in Python
+Home-page: https://numpy.org
+Author: Travis E. Oliphant et al.
+Author-email:
+License-Expression: BSD-3-Clause AND 0BSD AND MIT AND Zlib AND CC0-1.0
+Location: /Users/lastword/.local/share/mise/installs/python/3.12.12/lib/python3.12/site-packages
+Requires:
+Required-by:
+```

python/control-passing-of-time-in-tests.md

@@ -0,0 +1,40 @@
+# Control Passing Of Time In Tests
+
+While it is nice to be able to write pure functional code, our software still
+lives in the real world and may have to relate to or depend on the passing of
+time. In order to test this kind of code, we need time to behave in a reliable,
+deterministic way. One of the best ways to create a testing environment where
+that is true is to bring in tooling that hijacks time.
+
+The [`freezegun` module](https://github.com/spulec/freezegun) is a great tool
+for that job. We can use it to freeze time at a specific testable point, advance
+time a specific amount, and much more.
+
+Here is an example from the tests for [my CLI-based time tracking
+app](https://github.com/jbranchaud/py-vmt/blob/acb26e4840279d936a12f16c505ca7e75e9a6d20/tests/src/py_vmt/test_cli.py#L21)
+where I freeze time before starting a session. That gives me a chance to assert
+about the exact start time that is output by the command. Then I can advance
+time a little and assert that the `status` command outputs the correct thing.
+
+```python
+import datetime
+from freezegun import freeze_time
+
+# some other test setup omitted ...
+
+initial_datetime = datetime.datetime(
+    2026, 3, 14, 15, 5, 11, 0, datetime.timezone.utc
+)
+with freeze_time(initial_datetime) as frozen_datetime:
+    # start a session
+    start_result = runner.invoke(cli, ["start", "my-project"])
+    output = "Started tracking 'my-project' at 10:05AM"
+    assert output in start_result.output
+
+    frozen_datetime.tick(delta=datetime.timedelta(minutes=30))
+
+    # check status
+    status_result = runner.invoke(cli, ["status"])
+    output = "Tracking 'my-project' for 30m (since 10:05AM)"
+    assert output in status_result.output
+```

python/create-a-range-of-descending-values.md

@@ -0,0 +1,44 @@
+# Create A Range Of Descending Values
+
+A typical use of `range` looks something like this:
+
+```python
+>>> list(range(1, 5))
+[1, 2, 3, 4]
+```
+
+Which is equivalent to this one where we give a `step` value of `1`.
+
+```python
+>>> list(range(1, 5, 1))
+[1, 2, 3, 4]
+```
+
+If we try to create a _negative range_, that is, a range of values in decreasing
+order, we get an empty list.
+
+```python
+>>> list(range(0, -7))
+[]
+```
+
+That's because the `step` value still defaults to `1`. And there are no positive
+steps between `0` and `-7`. So, let's give `range` a `step` value of `-1`.
+
+```python
+>>> list(range(0,-7, -1))
+[0, -1, -2, -3, -4, -5, -6]
+```
+
+One practical use case of a negative range like this is using a list
+comprehension to transform it into a list of the _last seven days_.
+
+```python
+>>> from datetime import datetime, timedelta
+>>> [datetime.now().date() + timedelta(days=days) for days in range(0,-7, -1)]
+[datetime.date(2026, 3, 19), datetime.date(2026, 3, 18), datetime.date(2026, 3, 17), datetime.date(2026, 3, 16), datetime.date(2026, 3, 15), datetime.date(2026, 3, 14), datetime.date(2026, 3, 13)]
+```
+
+Of course this could have been written with a positive range and then
+subtracting the `timedelta`. I like that I have the option of doing this in
+whatever way makes the code most readable.

python/deduplicate-a-list-into-a-tuple.md

@@ -0,0 +1,46 @@
+# Deduplicate A List Into A Tuple
+
+A `list` is not hashable which means you can't use it for things like `dict`
+keys or cache keys. Instead you need to convert it into something like a `set`
+or a `tuple`.
+
+Here is an example list:
+
+```python
+>>> l1 = [3,4,1,2,5,4,1]
+```
+
+Turning this list into a `set` or `frozenset` is straightforward:
+
+```python
+>>> set(l1)
+{1, 2, 3, 4, 5}
+>>> frozenset(l1)
+frozenset({1, 2, 3, 4, 5})
+```
+
+If you're trying to preserve the order after deduplicating, then you'll want to
+use a `tuple` instead of a `set`. In order to deduplicate while maintaining the
+ordering, you can exploit the fact that `dict` keys maintain their order. A
+`list` can be transformed into the keys of a `dict` with
+[`dict.fromkeys`](https://docs.python.org/3/library/stdtypes.html#dict.fromkeys):
+
+```python
+>>> dict.fromkeys(l1)
+{3: None, 4: None, 1: None, 2: None, 5: None}
+```
+
+And here is your `tuple` which extracts the keys of the `dict`:
+
+```python
+>>> tuple(dict.fromkeys(l1))
+(3, 4, 1, 2, 5)
+```
+
+By comparison, here is the `tuple` transformed directly from the `list` without
+deduplication.
+
+```python
+>>> tuple(l1)
+(3, 4, 1, 2, 5, 4, 1)
+```

python/define-sequence-of-tests-with-parametrize-decorator.md

@@ -0,0 +1,60 @@
+# Define Sequence Of Tests With Parametrize Decorator
+
+I have a function that I want to test across a bunch of different inputs. That
+way I can make sure the logic of that function handles all the different
+scenarios I have in mind.
+
+While working on [`py-vmt`](https://github.com/jbranchaud/py-vmt), I started by
+writing a big single test function with a sequence of variable assignments and
+`assert` statements. Here's my starting point:
+
+```python
+def test_format_time_delta_everything():
+    # less than a minute
+    thirty_seconds = timedelta(seconds=30)
+    assert "30s" == format_time_delta(thirty_seconds)
+
+    # one minute exactly
+    one_minute = timedelta(seconds=60)
+    assert "1m" == format_time_delta(one_minute)
+
+    # more than a minute
+    assert "1m30s" == format_time_delta(one_minute + thirty_seconds)
+
+    # bunch of minutes and seconds
+    delta = timedelta(minutes=24, seconds=8)
+    assert "24m8s" == format_time_delta(delta)
+
+    # one hour exactly
+    one_hour = timedelta(hours=1)
+    assert "1h" == format_time_delta(one_hour)
+
+    # more than one hour
+    assert "1h24m" == format_time_delta(one_hour + delta)
+```
+
+I knew I would eventually need to break it up into individual test functions,
+but I couldn't bare to start there because it seemed quite repetitive.
+
+There is another way to approach this without all the duplication. Pytest comes
+with [a "parametrize" decorator](https://docs.pytest.org/en/stable/example/parametrize.html). This is
+used to define a set of test data (and expected values) that will get passed
+one-by-one to the test function as parameters.
+
+```python
+@pytest.mark.parametrize("input,expected", [
+    (timedelta(seconds=30), "30s"),
+    (timedelta(seconds=60), "1m"),
+    (timedelta(seconds=90), "1m30s"),
+    (timedelta(minutes=24, seconds=8), "24m8s"),
+    (timedelta(hours=1), "1h"),
+    (timedelta(hours=1, minutes=24, seconds=8), "1h24m"),
+])
+def test_format_time_delta(input, expected):
+    assert format_time_delta(input) == expected
+```
+
+I ditch all of the duplication this way. I define a list of tuples that
+represent my input values and expected values. Then the body of the test can be
+minimal. And I get a separate test execution for each parameter tuple making it
+easier to see fine-grained pass/fail results.

python/easy-key-value-aggregates-with-defaultdict.md

@@ -0,0 +1,53 @@
+# Easy Key-Value Aggregates With defaultdict
+
+The `collections` module has the `defaultdict` object that can be used to
+aggregate values tied to a key. What sets this apart from simply using a `dict`
+is that we get the base value for free. So if our aggregate value is a list,
+then we get `[]` by default for each new key. In the same way, we'd get `0` if
+it was constructed with `int`.
+
+Here is the counter example from [Keep A Tally With
+collections.Counter](keep-a-tally-with-collections-counter.md)
+
+```python
+from collections import defaultdict
+
+def get_pair_counts(token_ids: list[int]) -> Counter:
+    """Count how often each adjacent pair appears"""
+    counts = defaultdict(int)
+    for i in range(len(token_ids) - 1):
+        pair = (token_ids[i], token_ids[i + 1])
+        counts[pair] += 1
+    return counts
+```
+
+We never have to initially set a key to `0`. If the key is not yet present, then
+`int()` (the zero-value constructor) is used as the `__missing__` value.
+
+We can do the same with `list`:
+
+```python
+>>> import collections
+>>> stuff = collections.defaultdict(list)
+>>> stuff['alpha'].append(1)
+>>> stuff['alpha']
+[1]
+>>> stuff['beta']
+[]
+```
+
+In the same way, this uses `list()` as the `__missing__` value to start of each
+key with an `[]`.
+
+I find this so handy because in other languages I've typically had to do
+something more like this:
+
+```python
+words_by_length = {}
+for item in items:
+    if len(item) not in words_by_length:
+        words_by_length[len(item)] = []
+    words_by_length[len(item)].append(item)
+```
+
+This is much clunkier.

python/get-absolute-seconds-from-timedelta-object.md

@@ -0,0 +1,64 @@
+# Get Absolute Seconds From `timedelta` Object
+
+The [`timedelta` object provided by
+`datetime`](https://docs.python.org/3/library/datetime.html#timedelta-objects)
+is a useful built-in concept for representing a duration of time.
+
+```python
+>>> from datetime import timedelta
+>>> diff = timedelta(hours=1, minutes=1, seconds=6)
+>>> diff.seconds
+3666
+```
+
+It is pretty minimal though. There are only a couple things you can inspect
+about it -- `days`, `seconds` (as I did in the snippet above), and
+`microseconds`.
+
+And perhaps that is enough to hint at the issue I recently ran into with it --
+specifically that you can access both `days` and `seconds`.
+
+Let's look at what happens when I have a `timedelta` with more than a day worth
+of seconds.
+
+```python
+>>> diff = timedelta(seconds=(3600 * 24 + 1))
+>>> diff.seconds
+1
+>>> diff.days
+1
+```
+
+I thought `seconds` was going to produce `86401` instead of `1`. The reason is
+because any amount of duration over a day gets converted into the `days` value
+and its the remaining time smaller than a day that is represented by `seconds`.
+
+In my [original implementation of
+`format_time_delta`](https://github.com/jbranchaud/py-vmt/blob/c14eaa56cf5f5c6d0120a95f04f95a6c87443e1c/src/py_vmt/time_helpers.py#L11-L14),
+I was trying to build a relative time string by converting `seconds` into hours,
+minutes, and seconds. That approach falls apart as soon as the delta is greater
+than a day.
+
+```python
+def format_time_delta(diff) -> str:
+    hours, remainder = divmod(diff.seconds, 3600)
+    minutes, remainder = divmod(remainder, 60)
+    seconds = remainder
+
+    # ...
+```
+
+Instead, I needed to reach for [the `total_seconds()` function](https://docs.python.org/3/library/datetime.html#datetime.timedelta.total_seconds).
+This gives "the total number of seconds contained in the duration" and is
+described as equivalent to `diff / timedelta(seconds=1)`.
+
+Here is the [updated version of `format_time_delta`](https://github.com/jbranchaud/py-vmt/blob/ec1875a9d73552f5481e3945ddf522e94d0cc018/src/py_vmt/time_helpers.py?plain=1#L11-L16):
+
+```python
+def format_time_delta(diff: timedelta) -> str:
+    total_seconds = int(diff.total_seconds())
+
+    hours, remainder = divmod(total_seconds, 3600)
+    minutes, remainder = divmod(remainder, 60)
+    seconds = remainder
+```

python/get-quotient-and-remainder-in-one-operation.md

@@ -0,0 +1,42 @@
+# Get Quotient And Remainder In One Operation
+
+While writing some custom code to transform a number of seconds into the
+constituent hours, minutes, and seconds, I found myself needing to get both the
+quotient and remainder from a division between two numbers.
+
+```python
+>>> import math
+>>> math.floor(3666 / 3600)
+1
+>>> 3666 % 3600
+66
+```
+
+Instead, I can use Python's built-in
+[`divmod`](https://docs.python.org/3/library/functions.html#divmod) function to
+compute both values in one statement.
+
+```python
+>>> divmod(3666, 3600)
+(1, 66)
+```
+
+The result is a tuple with the first value being my quotient (in this case, the
+number of hours) and the remainder (the remaining number of seconds).
+
+This kind of operation is known as [Euclidian
+Division](https://en.wikipedia.org/wiki/Euclidean_division).
+
+Here is a snippet of some actual code where I use this in
+[`py-vmt`](https://github.com/jbranchaud/py-vmt/blob/b9eae8b258e9fd720cfa3bb63b601225df352051/src/py_vmt/time_helpers.py#L14-L16):
+
+```python
+def format_time_delta(diff: timedelta) -> str:
+    total_seconds = int(diff.total_seconds())
+
+    hours, remainder = divmod(total_seconds, 3600)
+    minutes, remainder = divmod(remainder, 60)
+    seconds = remainder
+
+    # ...
+```

python/install-with-pip-for-specific-interpreter.md

@@ -0,0 +1,17 @@
+# Install With PIP For Specific Interpreter
+
+The `pip` module can be invoked for any of its commands, such as install, using
+a specific Python interpreter like so:
+
+```bash
+$ python3 -m pip install black
+```
+
+This avoid ambiguity between the version of Python I am using and version of the
+package manager I'm using.
+
+Similarly if I need to upgrade `pip`, I can do the following:
+
+```bash
+$ python3 -m pip install --upgrade pip
+```

python/iterate-first-n-items-from-enumerable.md

@@ -0,0 +1,27 @@
+# Iterate First N Items From Enumerable
+
+As I'm working through the 2nd chapter of [Build a Large Language Model (from
+scratch)](https://still.visualmode.dev/blogmarks/227), I came across a code
+example processing a dictionary of words. This example used a for loop to print
+out each dictionary entry until an index of 50 was reached on then it did a
+`break`.
+
+This struck me as an odd way to grab and process N items from a list. I did some
+searching and found `itertools` which provides
+[`islice`](https://docs.python.org/3/library/itertools.html#itertools.islice).
+
+```python
+from itertools import islice
+
+# preprocess words from a file into a word list
+all_words = ... # not shown here
+
+vocab = {token: integer for integer, token in enumerate(all_words)}
+for item in islice(enumerate(vocab.items()), 50):
+    print(item)
+```
+
+The `islice` function is a better approach because the intention (to grab the
+first 50 things) is encoded in the function call rather than buried in a loop
+body. It also has equivalent memory efficiency to the original example because
+it lazily processes the list of `vocab` items.

python/iterate-over-a-dictionary.md

@@ -0,0 +1,34 @@
+# Iterate Over A Dictionary
+
+Let's say we have a `dict` that contains counts of occurrences for each word in
+some sample text:
+
+```python
+words_frequency = {
+    "the": 4,
+    "a": 3,
+    "dog": 1,
+    "bone": 1,
+    "wants": 1,
+    ...
+}
+```
+
+Here is how we can iterate over the `dict`, accessing both the keys and values:
+
+```python
+for word, count in word_frequency.items():
+    print(f"- {word} appears {count} time{'' if count == 1 else 's'}")
+```
+
+Using the
+[`items()`](https://docs.python.org/3/library/stdtypes.html#dict.items) method,
+we're able to access both _key_ and _value_ with the for loop as it iterates.
+
+Another approach is to loop directly on the `dict` which implicitly surfaces the
+_key_ for iteration. This can then be used to get the value from the `dict`:
+
+```python
+for word in word_frequency:
+    print(f"- {word}: {word_frequency[word]}
+```

python/keep-a-tally-with-collections-counter.md

@@ -0,0 +1,40 @@
+# Keep A Tally With collections.Counter
+
+Python's `collections` module comes with a
+[`Counter`](https://docs.python.org/3/library/collections.html#collections.Counter)
+object which is a specialized dict subclass focussed on tallying counts of keys.
+
+> It is a collection where elements are stored as dictionary keys and their
+> counts are stored as dictionary values. Counts are allowed to be any integer
+> value including zero or negative counts.
+
+I used it recently while doing an exploratory implementation of a Byte-Pair
+Encoding (BPE):
+
+```python
+from collections import Counter
+
+def get_pair_counts(token_ids: list[int]) -> Counter:
+    """Count how often each adjacent pair appears"""
+    counts = Counter()
+    for i in range(len(token_ids) - 1):
+        pair = (token_ids[i], token_ids[i + 1])
+        counts[pair] += 1
+    return counts
+```
+
+Here I'm able to count the number of occurrences of each pair of bytes from the
+input text. A tuple of `int` values is hashable, so they work great as keys for
+a `Counter`.
+
+The count value of any key will default to `0`. That makes it straightforward to
+increment from there as you iterating over occurrences.
+
+```python
+>>> counts = Counter()
+>>> counts['hello']
+0
+>>> count['hello'] += 1
+>>> count['hello']
+1
+```

python/load-a-file-into-the-python-repl.md

@@ -0,0 +1,35 @@
+# Load A File Into The Python REPL
+
+I opened up a Python REPL to try some things out.
+
+```
+$ python3
+>>> import math
+>>> math.floor(5/2)
+2
+```
+
+Now, I want to reference a Python file I've been working on so that I can
+manually test the behavior of what I'm building. To do this, I can import a file
+by its name in the same way that I would import any module. Then I can use that
+namespace for class and method references. Crucially, the file should exist in
+the same directory the REPL was started from.
+
+First, here is the file:
+
+```python
+# bpe.py
+class BytePairEncoding:
+    def text_to_bytes(text: str) -> list[int]:
+        """Convert a string to a list of byte values (0-255)"""
+        return list(text.encode("utf-8"))
+```
+
+Now to use it from the REPL:
+
+```
+$ python
+>>> import bpe
+>>> bpe.BytePairEncoding.text_to_bytes("Gimme some bytes!")
+[71, 105, 109, 109, 101, 32, 115, 111, 109, 101, 32, 98, 121, 116, 101, 115, 33]
+```

python/look-inside-pytest-tmp-path.md

@@ -0,0 +1,41 @@
+# Look Inside Pytest tmp_path
+
+In [Isolate and Debug File Side-Effects with Pytest
+`tmp_path`](https://www.visualmode.dev/isolate-and-debug-file-side-effects-with-pytest-tmp-path),
+I wrote about how I use
+[`tmp_path`](https://docs.pytest.org/en/stable/reference/reference.html#std-fixture-tmp_path)
+in a Pytest fixture to test [my `py-vmt` CLI](https://github.com/jbranchaud/py-vmt). During testing of the CLI interface
+via [`click`'s testing utilities](https://click.palletsprojects.com/en/stable/testing/), `vmt` creates,
+modifies, and reads from files. Isolating that behavior with the `tmp_path`
+fixture is useful because it prevents individual test cases from conflicting
+with one another.
+
+Here is what the fixture looks like at the top of my test file:
+
+```python
+# auto fixture for all test cases that monkeypatches the platform dirs to a tmp
+# path so that test side-effects don't persist between runs
+@pytest.fixture(autouse=True)
+def use_tmp_platform_dirs(tmp_path, monkeypatch):
+    data_dir = tmp_path / "data"
+    config_dir = tmp_path / "config"
+    data_dir.mkdir()
+    config_dir.mkdir()
+    monkeypatch.setattr(CliContext, "get_data_dir", staticmethod(lambda: data_dir))
+    monkeypatch.setattr(CliContext, "get_config_dir", staticmethod(lambda: config_dir))
+```
+
+The root of the temp directory is located at `tempfile.gettempdir()` and the
+directories from there are organized with this structure:
+
+```
+{temproot}/pytest-of-{user}/pytest-{num}/{testname}/
+```
+
+So, in the case of `vmt`, I can find the `config` and `data` dirs for a specific
+test run here:
+
+```bash
+❯ ls /var/folders/zc/q6gnvbgx6kq77828jn38716r0000gn/T/pytest-of-lastword/pytest-2/test_start_status_stop_flow0
+config data
+```

python/make-dataclass-sortable-by-specific-field.md

@@ -0,0 +1,45 @@
+# Make Dataclass Sortable By Specific Field
+
+One way to sort a list of some `dataclass` is to define the `key` parameter when
+calling `sort` or `sorted` like I discussed in [Sort a List of Dataclass
+Instances](sort-a-list-of-dataclass-instances.md):
+
+```python
+for date in sessions_grouped_by_day.keys():
+    sessions_grouped_by_day[date].sort(
+        key=lambda session: session.start_time.time()
+    )
+```
+
+But then that lambda for `key` needs to be defined everywhere you sort.
+
+If the dataclass has a single, specific field that acts as a natural proxy for
+sort order, then you can define that in the `dataclass` implementation with the
+`__lt__` method.
+
+As long as a class defines the _less than_ dunder method, it will be sortable.
+
+Here is what that looks like for this `Session` dataclass:
+
+```python
+from dataclasses import dataclass
+from datetime import datetime, timezone
+
+@dataclass
+class Session:
+    start_time: datetime
+    project_name: str
+    end_time: datetime | None = None
+
+    def __lt__(self, other):
+        if not isinstance(other, Session):
+            return NotImplemented
+        return self.start_time < other.start_time
+
+    # more methods below ...
+```
+
+This implementation of `__lt__` tells the sorting methods that _this_ (`self`)
+instance of `Session` can be compared to some `other` instance of `Session` by
+comparing their `start_time` values to see which is less than. The guard at the
+beginning makes sure only instances of `Session` are being compared.

python/parse-relative-time-to-datetime-object.md

@@ -0,0 +1,62 @@
+# Parse Relative Time To datetime Object
+
+I was looking for an out-of-the-box solution for parsing natural language,
+relative time strings (e.g. `'33 minutes ago'`) into valid `datetime` objects.
+The best library for this is
+[`dateparser`](https://dateparser.readthedocs.io/en/latest/).
+
+While it is as easy to use this as _import_ then _parse_:
+
+```python
+>>> import dateparser
+>>> dateparser.parse('33 minutes ago')
+datetime.datetime(2026, 3, 7, 23, 19, 9, 17855)
+```
+
+There is more to it if we need to deal with timezones.
+
+In my use case, I wanted to my `datetime` object to be timezone-aware and I
+wanted to store it in `UTC`.
+
+As is, the above simple `datetime` object is not `tzaware`, meaning it doesn't
+have any `tzinfo` attached to it.
+
+```python
+>>> dateparser.parse('33 minutes ago').tzinfo is not None
+False
+```
+
+We need to pass some additional settings during `parse`.
+
+```python
+>>> settings = {'RETURN_AS_TIMEZONE_AWARE': True}
+>>> dateparser.parse('33 minutes ago', settings=settings)
+>>> _
+datetime.datetime(2026, 3, 8, 9, 53, 36, 225099, tzinfo=zoneinfo.ZoneInfo(key='America/Chicago'))
+>>> settings['TO_TIMEZONE'] = 'UTC'
+>>> dateparser.parse('33 minutes ago', settings=settings)
+>>> _
+datetime.datetime(2026, 3, 8, 14, 54, 47, 34041, tzinfo=<StaticTzInfo 'UTC'>)
+```
+
+The first step to getting a `datetime` object that is `tzaware` is to set
+`RETURN_AS_TIMEZONE_AWARE` to `True`. That picks up the locale setting of the
+system it is running on -- in my case, I'm in Chicago.
+
+I said I wanted to store this as UTC though. That means I need to pass an
+additional setting `TO_TIMEZONE` with a value of `'UTC'` which will translate
+the `datetime` from my local time to UTC -- notice the 5 hour difference from
+`9` to `14`.
+
+Storing `datetime` details like this with timezone info _as_ UTC is nice because
+it keeps everything consistent at the storage layer and then at the presentation
+layer I can always convert it right back to the local timezone with
+`astimezone`.
+
+```python
+>>> _.astimezone()
+datetime.datetime(2026, 3, 8, 9, 54, 47, 34041, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=68400), 'CDT'))
+```
+
+See the [`datetime` docs](https://docs.python.org/3/library/datetime.html) for
+more details.

python/reclassify-certain-packages-as-dev-dependencies.md

@@ -0,0 +1,76 @@
+# Reclassify Certain Packages As Dev Dependencies
+
+When I first started working on [py-vmt](https://github.com/jbranchaud/py-vmt),
+I wasn't differentiating certain test packages as _dev_ dependencies as opposed
+to standard, production dependencies. This can lead to bloated installs across a
+variety of distribution channels.
+
+Notice that I have everything treated as production dependencies:
+
+```bash
+❯ uv tree --no-dev
+Resolved 18 packages in 2ms
+py-vmt v0.1.0
+├── click v8.3.1
+├── dateparser v1.3.0
+│   ├── python-dateutil v2.9.0.post0
+│   │   └── six v1.17.0
+│   ├── pytz v2026.1.post1
+│   ├── regex v2026.2.28
+│   └── tzlocal v5.3.1
+├── freezegun v1.5.5
+│   └── python-dateutil v2.9.0.post0 (*)
+├── platformdirs v4.9.4
+├── pytest v9.0.2
+│   ├── iniconfig v2.3.0
+│   ├── packaging v26.0
+│   ├── pluggy v1.6.0
+│   └── pygments v2.19.2
+└── types-dateparser v1.3.0.20260211
+(*) Package tree already displayed
+```
+
+`pytest`, `freezegun`, and `types-dateparser` are better suited as _dev_
+dependencies.
+
+I can reclassify them by moving them from `dependencies` into a `dev` dependency
+group in `pyproject.toml`:
+
+```toml
+dependencies = ["click>=8.3.1", "dateparser>=1.3.0", "platformdirs>=4.9.4"]
+[dependency-groups]
+dev = ["freezegun>=1.5.5", "pytest>=9.0.2", "types-dateparser>=1.3.0.20260211"]
+```
+
+I only had `dependencies` before, so I had to add `[dependency-groups]` and `dev = []` to my `pyproject.toml` file.
+
+I can then tell `uv` to sync up the installation and virtualenv based on the new
+organization of the dependencies.
+
+```bash
+❯ uv sync
+warning: Skipping installation of entry points (`project.scripts`) because this project is not packaged; to install entry points, set `tool.uv.package = true` or define a `build-system`
+Resolved 18 packages in 518ms
+```
+
+Now when I check the `--no-dev` tree of dependencies, it's just the essentials:
+
+```bash
+❯ uv tree --no-dev
+Resolved 18 packages in 1ms
+py-vmt v0.1.0
+├── click v8.3.1
+├── dateparser v1.3.0
+│   ├── python-dateutil v2.9.0.post0
+│   │   └── six v1.17.0
+│   ├── pytz v2026.1.post1
+│   ├── regex v2026.2.28
+│   └── tzlocal v5.3.1
+└── platformdirs v4.9.
+```
+
+Another way to achieve this would have been to run `uv remove` and `uv add` with
+the relevant sets of package names. In retrospect, I would have preferred using
+that approach in the first place. If you're wanting to be pinned to specific
+versions of certain packages, you'd have to be a little more careful to get this
+right.

python/skip-specific-pytest-test-cases.md

@@ -0,0 +1,38 @@
+# Skip Specific Pytest Test Cases
+
+While using a failing test case to build a small new feature for
+[`py-vmt`](https://github.com/jbranchaud/py-vmt), I realized I needed to do some
+refactoring first. It wasn't significant enough to warrant stashing my current
+changes and switching to a different branch, so I kept all the changes around. I
+did find the initial failing test distracting from the refactoring I was trying
+to do. To temporarily shelve that failure, I can use a Pytest decorator to mark
+it as _skipped_.
+
+```python
+@pytest.mark.skip(reason="not yet implemented")
+def test_log_recent_activity():
+    runner = CliRunner()
+
+    # set up the data dir file with some existing session entries
+    initial_datetime = datetime.datetime(
+        2026, 3, 14, 15, 5, 11, 0, datetime.timezone.utc
+    )
+    with freeze_time(initial_datetime) as frozen_datetime:
+        # ...
+```
+
+The [`@pytest.mark.skip` decorator](https://docs.pytest.org/en/stable/how-to/skipping.html#skipping-test-functions)
+tells the Pytest runner to skip of that specific test case instead of executing
+it. In the test runner output, I'll see an `s` rather than a `.` or `F` and the
+summary will include it in a count of skipped tests:
+
+```
+=========================== 3 failed, 4 passed, 1 skipped in 0.09s ===========================
+```
+
+Another way to think about this is to mark this test case as _expected to fail_
+with `@pytest.mark.xfail`. That will display as an `x` and show up in the summary as:
+
+```
+=========================== 3 failed, 4 passed, 1 xfailed in 0.11s ===========================
+```

python/sort-a-list-of-dataclass-instances.md

@@ -0,0 +1,52 @@
+# Sort A List Of Dataclass Instances
+
+Sorting lists of scalar values (integers, strings, floats, even booleans) in
+Python is simple because the natural ordering of the list elements will be used.
+We can call `sorted` on the list and it _just works_.
+
+```python
+>>> items = ["orange", "apple", "banana", "mango"]
+>>> sorted(items)
+['apple', 'banana', 'mango', 'orange']
+```
+
+However, if we have a list of non-scalar values, it is a little more complex. We
+have to give `sorted` some help with knowing how to sort things that don't have
+a natural ordering.
+
+Let's take this `dataclass` that represents a time-based `Session` as an
+example.
+
+```python
+from dataclasses import dataclass
+from datetime import datetime, timezone
+
+@dataclass
+class Session:
+    start_time: datetime
+    project_name: str
+    end_time: datetime | None = None
+
+    # plus several methods ...
+```
+
+If I have a list of `Session` instances that I want to sort, I have to give
+`sorted` a `key` to sort on. In the case of these `Session` instances, we'll
+pass a `lambda` that can be evaluated to determine the sort value (which needs
+to be sortable). `datetime` instances are sortable and I want to sort these
+sessions based on their `start_time` values.
+
+Here is a snippet from my `py_vmt` CLI where I make sure that each list of
+sessions in this day-by-day `dict` is sorted based on the `start_time`:
+
+```python
+for date in sessions_grouped_by_day.keys():
+    sessions_grouped_by_day[date].sort(
+        key=lambda session: session.start_time.time()
+    )
+```
+
+`sort` (and `sorted`) translates each item in the list to the values produced
+by the lambda and then sorts them by those values.
+
+[source](https://docs.python.org/3/howto/sorting.html)

python/sort-normalized-version-of-data.md

@@ -0,0 +1,33 @@
+# Sort Normalized Version Of Data
+
+Let's say I have a list of names that I want to sort. However, because of
+inconsistency in how the data was entered, sometimes those names are capitalized
+and other times they are not. Using
+[`methodcaller`](https://docs.python.org/3/library/operator.html#operator.methodcaller),
+I can normalize the sorting `key` used when comparing list items.
+
+First, let's look at calling `sorted` with the list and no `key`:
+
+```python
+>>> sorted(["butler", "Jemisin", "le guin", "Erdrich"])
+['Erdrich', 'Jemisin', 'butler', 'le guin']
+```
+
+`butler` which starts with a `b` gets moved to the 3rd position because it is
+lowercase.
+
+To sort this list using a normalized comparison, we will use `methodcaller` to
+create a callable out of `lower` which is then passed as the sort `key`:
+
+```python
+>>> from operator import methodcaller
+>>> sorted(["butler", "Jemisin", "le guin", "Erdrich"], key=methodcaller("lower"))
+['butler', 'Erdrich', 'Jemisin', 'le guin']
+```
+
+That's the sort order I was originally hoping for.
+
+What `methodcaller` is doing is creating a callable function that will invoke
+`lower` with each string instance as the target. Conceptually similar to
+`"Erdrich".lower()` or even `getattr("Erdrich", "lower")()` (notice this needs
+to be immediately invoked).

python/start-the-debugger-when-a-test-errors.md

@@ -0,0 +1,27 @@
+# Start The Debugger When A Test Errors
+
+While working on [some
+tests](https://github.com/jbranchaud/build-an-llm-from-scratch/blob/main/tests/chapter_02/test_bpe_tokenizer.py)
+for my Byte Pair Encoding tokenizer, I was running into an unexpected test
+failure. To better understand what was going on, I needed to inspect the state
+of the program around the time the code raised an exception.
+
+Instead of needing to manually set a breakpoint at the correct spot to begin
+debugging, I can run the test with the Pytest-supported `--pdb` flag. That's
+short for _python debugger_.
+
+> Start the interactive Python debugger on errors or KeyboardInterrupt
+
+What this does during a test run is opens you up to the interactive Python
+debugger at the exact moment an exception is raised. This gives you the ability
+to inspect values of the program state at that point in execution which could
+help inform the needed fix.
+
+```bash
+uv run pytest -vv --pdb -k "test_train_bpe"
+```
+
+There I am running a specific test that matches against `-k "test_train_bpe"`
+and the python debugger will start up if there is an error.
+
+See `uv run pytest --help` for more details.

python/use-post-init-for-dataclass-validations.md

@@ -0,0 +1,54 @@
+# Use `__post_init__` For `dataclass` Validations
+
+The [`dataclass`](https://docs.python.org/3/library/dataclasses.html) construct
+is a handy stdlib way of modeling some data with many improvements over a `dict`
+such as named attributes and type visibility.
+
+```python
+from dataclasses import dataclass
+from typing import ClassVar
+
+@dataclass
+class BPEConfig:
+    BASE_VOCAB_SIZE: ClassVar[int] = 256
+
+    vocab_size: int
+    special_tokens: list[str]
+```
+
+I want to enhance `BPEConfig` a little by validating the `vocab_size` which
+cannot be less than the `BASE_VOCAB_SIZE`. The
+[`__post_init__`](https://docs.python.org/3/library/dataclasses.html#dataclasses.__post_init__)
+method is a good place for this kind of validation.
+
+```python
+from dataclasses import dataclass
+from typing import ClassVar
+
+@dataclass
+class BPEConfig:
+    BASE_VOCAB_SIZE: ClassVar[int] = 256
+
+    vocab_size: int
+    special_tokens: list[str]
+
+    def __post_init__(self):
+        if self.vocab_size < self.BASE_VOCAB_SIZE:
+            msg = f"vocab_size ({self.vocab_size}) must be greater than or equal to BASE_VOCAB_SIZE ({self.BASE_VOCAB_SIZE})"
+            raise ValueError(msg)
+```
+
+With this in place, my program will fail fast if I try to use an invalid
+`vocab_size`:
+
+```python
+>>> BPEConfig(22, [])
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+  File "<string>", line 5, in __init__
+  File "/Users/lastword/dev/misc/build-an-llm/chapter_02/bpe_tokenizer.py", line 24, in __post_init__
+    raise ValueError(msg)
+ValueError: vocab_size (22) must be greater than or equal to BASE_VOCAB_SIZE (256)
+```
+
+This example is pulled directly from [the `BPETokenizer` I'm building](https://github.com/jbranchaud/build-an-llm-from-scratch/blob/d3fd0acd65c3e7419b2d15a64c8d74266d0488f6/chapter_02/bpe_tokenizer.py#L14-L24).

python/use-verbose-flag-to-get-more-diff.md

@@ -0,0 +1,161 @@
+# Use Verbose Flag To Get More Diff
+
+Here is the output of running some `pytest` unit tests. A couple of the tests
+pass, which produces little output. But I get a big block of details for the one
+failing test. In this case the failure is an assertion between two lists that
+don't match.
+
+```bash
+❯ uv run pytest
+========================================== test session starts ==========================================
+platform darwin -- Python 3.12.12, pytest-9.0.2, pluggy-1.6.0
+rootdir: /Users/lastword/dev/misc/build-an-llm
+configfile: pyproject.toml
+collected 3 items
+
+tests/chapter_02/test_bpe_tokenizer.py .F.                                                        [100%]
+
+=============================================== FAILURES ================================================
+_____________________________________ test_merge_with_byte_sequence _____________________________________
+
+    def test_merge_with_byte_sequence():
+        token_ids = [1, 2, 3, 4, 5, 2, 3, 1, 2, 3, 4, 1]
+        merged_tokens = BPETokenizer._merge(token_ids, [2, 3, 4], 256)
+        # assert merged_tokens == [1, 256, 5, 2, 3, 1, 256, 1]
+>       assert merged_tokens == [1, 256, 5, 4, 5, 1, 256, 1]
+E       assert [1, 256, 5, 2, 3, 1, ...] == [1, 256, 5, 4, 5, 1, ...]
+E
+E         At index 3 diff: 2 != 4
+E         Use -v to get more diff
+
+tests/chapter_02/test_bpe_tokenizer.py:13: AssertionError
+======================================== short test summary info ========================================
+FAILED tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_sequence - assert [1, 256, 5, 2, 3, 1, ...] == [1, 256, 5, 4, 5, 1, ...]
+====================================== 1 failed, 2 passed in 0.02s ======================================
+```
+
+The lists are too long to fully display in the failure output. `pytest` is able
+to tell us two useful things though. First, it mentions that the first
+discrepancy in the lists is at index `3` where `2 != 4`. Second, it says `Use -v
+to get more diff`.
+
+Let's try rerunning the tests with `-v`.
+
+```bash
+❯ uv run pytest -v
+========================================== test session starts ==========================================
+platform darwin -- Python 3.12.12, pytest-9.0.2, pluggy-1.6.0 -- /Users/lastword/dev/misc/build-an-llm/.venv/bin/python3
+cachedir: .pytest_cache
+rootdir: /Users/lastword/dev/misc/build-an-llm
+configfile: pyproject.toml
+collected 3 items
+
+tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_pair PASSED                          [ 33%]
+tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_sequence FAILED                      [ 66%]
+tests/chapter_02/test_bpe_tokenizer.py::test_subsequence_at_index PASSED                          [100%]
+
+=============================================== FAILURES ================================================
+_____________________________________ test_merge_with_byte_sequence _____________________________________
+
+    def test_merge_with_byte_sequence():
+        token_ids = [1, 2, 3, 4, 5, 2, 3, 1, 2, 3, 4, 1]
+        merged_tokens = BPETokenizer._merge(token_ids, [2, 3, 4], 256)
+        # assert merged_tokens == [1, 256, 5, 2, 3, 1, 256, 1]
+>       assert merged_tokens == [1, 256, 5, 4, 5, 1, 256, 1]
+E       AssertionError: assert [1, 256, 5, 2, 3, 1, ...] == [1, 256, 5, 4, 5, 1, ...]
+E
+E         At index 3 diff: 2 != 4
+E
+E         Full diff:
+E           [
+E               1,
+E               256,...
+E
+E         ...Full output truncated (13 lines hidden), use '-vv' to show
+
+tests/chapter_02/test_bpe_tokenizer.py:13: AssertionError
+======================================== short test summary info ========================================
+FAILED tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_sequence - AssertionError: assert [1, 256, 5, 2, 3, 1, ...] == [1, 256, 5, 4, 5, 1, ...]
+====================================== 1 failed, 2 passed in 0.02s ======================================
+```
+
+That was sort of a tease because it starts to display a "Full diff", but that
+gets quickly truncated. `pytest` then tells us that we can `use '-vv' to show`
+the full diff.
+
+```bash
+❯ uv run pytest -vv
+========================================== test session starts ==========================================
+platform darwin -- Python 3.12.12, pytest-9.0.2, pluggy-1.6.0 -- /Users/lastword/dev/misc/build-an-llm/.venv/bin/python3
+cachedir: .pytest_cache
+rootdir: /Users/lastword/dev/misc/build-an-llm
+configfile: pyproject.toml
+collected 3 items
+
+tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_pair PASSED                          [ 33%]
+tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_sequence FAILED                      [ 66%]
+tests/chapter_02/test_bpe_tokenizer.py::test_subsequence_at_index PASSED                          [100%]
+
+=============================================== FAILURES ================================================
+_____________________________________ test_merge_with_byte_sequence _____________________________________
+
+    def test_merge_with_byte_sequence():
+        token_ids = [1, 2, 3, 4, 5, 2, 3, 1, 2, 3, 4, 1]
+        merged_tokens = BPETokenizer._merge(token_ids, [2, 3, 4], 256)
+        # assert merged_tokens == [1, 256, 5, 2, 3, 1, 256, 1]
+>       assert merged_tokens == [1, 256, 5, 4, 5, 1, 256, 1]
+E       assert [1, 256, 5, 2, 3, 1, 256, 1] == [1, 256, 5, 4, 5, 1, 256, 1]
+E
+E         At index 3 diff: 2 != 4
+E
+E         Full diff:
+E           [
+E               1,
+E               256,
+E               5,
+E         -     4,
+E         ?     ^
+E         +     2,
+E         ?     ^
+E         -     5,
+E         ?     ^
+E         +     3,
+E         ?     ^
+E               1,
+E               256,
+E               1,
+E           ]
+
+tests/chapter_02/test_bpe_tokenizer.py:13: AssertionError
+======================================== short test summary info ========================================
+FAILED tests/chapter_02/test_bpe_tokenizer.py::test_merge_with_byte_sequence - assert [1, 256, 5, 2, 3, 1, 256, 1] == [1, 256, 5, 4, 5, 1, 256, 1]
+
+  At index 3 diff: 2 != 4
+
+  Full diff:
+    [
+        1,
+        256,
+        5,
+  -     4,
+  ?     ^
+  +     2,
+  ?     ^
+  -     5,
+  ?     ^
+  +     3,
+  ?     ^
+        1,
+        256,
+        1,
+    ]
+====================================== 1 failed, 2 passed in 0.02s ======================================
+```
+
+This is a lot more output to look at. What we can perhaps see more clearly now
+is that the lists match up until there is a mismatch between `2` and `4` at the
+third index. And then right after that is another mismatch between `3` and `5`.
+
+This kind of output can only scale so much, so use it when it works and when the
+diff view starts to fall short, rework the assertions to get more readable and
+actionable test output.

rails/check-how-database-is-configured.md

@@ -0,0 +1,46 @@
+# Check How Database Is Configured
+
+While making some adjustments to the database connection string (`DATABASE_URL`)
+for a pre-production Rails environment, we wanted to check that configuration
+options like `sslmode` were picked up.
+
+From a `rails console` session I can check the live database configuration like
+so:
+
+```ruby
+> ActiveRecord::Base.connection_db_config.configuration_hash
+=> {
+  adapter: "postgresql",
+  encoding: "unicode",
+  pool: 5,
+  database: "my_app_development"
+}
+```
+
+I can look at the
+[`configuration_hash`](https://api.rubyonrails.org/classes/ActiveRecord/DatabaseConfigurations/HashConfig.html#attribute-i-configuration_hash)
+from `rails console` of my pre-prod environment to see more configuration
+settings:
+
+```ruby
+> ActiveRecord::Base.connection_db_config.configuration_hash
+=> {
+  adapter: "postgresql",
+  encoding: "unicode",
+  pool: 5,
+  username: "app_user",
+  password: "super_s3cr3t",
+  port: 15432,
+  database: "pre_prod_database",
+  host: "some-host-123.ondigitalocean.com",
+  sslmode: "verify-full"
+}
+```
+
+Since I was specifically looking for the `sslmode` value, I can access that
+directly:
+
+```ruby
+> ActiveRecord::Base.connection_db_config.configuration_hash[:sslmode]
+=> "verify-full"
+```

rails/check-the-current-named-log-level.md

@@ -0,0 +1,46 @@
+# Check The Current Named Log Level
+
+I'm connected to a `rails console` session for an active Rails app. I want to
+check the current log level.
+
+```ruby
+> Rails.logger.level
+=> 1
+```
+
+The `1` doesn't mean much to me at a glance. I can translate that to the
+severity level using the `Logger::SEV_LABLE` constant.
+
+```ruby
+[44] pry(main)> Logger::SEV_LABEL[Rails.logger.level]
+=> "INFO"
+```
+
+Ah yes, `INFO`, that makes sense as the default.
+
+I can see all the severity levels by inspecting the constant itself.
+
+```ruby
+[45] pry(main)> Logger::SEV_LABEL
+=> ["DEBUG", "INFO", "WARN", "ERROR", "FATAL", "ANY"]
+```
+
+As I convenience, I can set the label using the index, the string, or even a
+symbol.
+
+```ruby
+> Rails.logger.level
+=> 1
+> Rails.logger.level = "WARN"
+=> "WARN"
+> Rails.logger.level
+=> 2
+> Rails.logger.level = :debug
+=> :debug
+> Rails.logger.level
+=> 0
+```
+
+See the [Debugging Rails Applications
+guide](https://guides.rubyonrails.org/debugging_rails_applications.html#log-levels)
+for more details.

rails/clean-up-memory-hungry-rails-console-processes.md

@@ -0,0 +1,43 @@
+# Clean Up Memory Hungry Rails Console Processes
+
+I noticed (using `htop`) that a remote server hosting a Rails app had most of
+its RAM being actively consumed. This was hindering my ability to run a fresh
+deploy because the deploy processes had to do a ton of memory swapping which
+drastically slowed the whole thing down.
+
+With some investigation, I discovered that most of the memory was being consumed
+by a handful of `rails console` processes. I didn't have any known active `rails console` processes that I was using. That combined with the dates of these
+processes starting way in the past suggested to me that these were abandoned
+processes that hadn't been properly cleaned up.
+
+```bash
+server:~# ps aux | grep rails
+32767     878915  0.0  0.0 1227160  936 pts/0    Ssl+  2025   0:03 /exec rails console
+32767     878942  0.9  6.5 830996 261748 pts/0   Rl+   2025 249:51 ruby /app/bin/rails console
+32767    3004097  0.0  0.0 1227160  692 pts/0    Ssl+  2025   0:04 /exec rails console
+32767    3004129  0.9  6.4 834672 257228 pts/0   Dl+   2025 406:31 ruby /app/bin/rails console
+32767    3048582  0.0  0.0 1227160  940 pts/0    Ssl+ Jan09   0:00 /exec rails console
+32767    3048611  1.1  6.3 829936 253484 pts/0   Dl+  Jan09  60:50 ruby /app/bin/rails console
+32767    3060033  0.0  0.0 1227160  944 pts/0    Ssl+  2025   0:04 /exec rails console
+32767    3060063  0.9  6.5 838084 260812 pts/0   Rl+   2025 405:37 ruby /app/bin/rails console
+root     3699372  0.0  0.0   7008  1300 pts/0    S+   15:51   0:00 grep --color=auto rails
+server:~# ps aux | grep 'rails console' | awk '{sum+=$6} END {print sum/1024 " MB"}'
+1014.64 MB
+```
+
+As we can see by tacking on this `awk` command, these processes are consuming
+1GB of memory.
+
+Each of these is a pair of processes. A parent process (`/exec rails console`)
+that kicks off and supervises the memory-hungry child process (`ruby /app/bin/rails console`).
+
+To free up this memory, I targeted each of the parent processes with a `kill`
+command one by one. For example:
+
+```bash
+server:~# kill 878915
+```
+
+I suspect that I may have left the occasional terminal tab open with one of
+these `rails console` processes running and the SSH connection was getting
+killed without the `rails console` getting killed with it.

ruby/define-a-set-of-class-methods.md

@@ -0,0 +1,46 @@
+# Define A Set Of Class Methods
+
+The most common way to define class methods is by defining them directly with
+`self` (the class in the current context) on a method by method basis:
+
+```ruby
+class User
+  def self.find_by(attrs)
+    # lookup logic ...
+  end
+end
+```
+
+If you have a group of class methods you want to define, you can stick them all
+within a `class << self` block which does similarly defines each of them as
+singleton methods of that class (`User` in this case):
+
+```ruby
+class User
+  class << self
+    def find_by_email(email)
+      # lookup logic ...
+    end
+
+    def find_by_last_name(last_name)
+      # lookup logic ...
+    end
+  end
+end
+```
+
+This opens the singleton class of `User` for modification, adding these two new
+methods.
+
+We can see those defined alongside all other direct and inherited class methods:
+
+```ruby
+> User.methods
+=>
+[:find_by_email,
+ :find_by_last_name,
+ :yaml_tag,
+ :allocate,
+ ...
+]
+```

ruby/filter-by-type.md

@@ -0,0 +1,37 @@
+# Filter By Type
+
+In Ruby, we have several ways to check if something is a certain type (class or
+subclass). A couple common approaches you might see are `#is_a?` and `===`
+(case equality operator):
+
+```ruby
+> 3.is_a?(Integer)
+=> true
+> Integer === 3
+=> true
+> 3 === Integer
+=> false
+```
+
+Notice it is important to get the ordering of class and value right when using
+`===`.
+
+We can use these concepts to filter collections down to just those values of a
+certain type. We can also ditch those methods and instead use
+[`#grep`](https://ruby-doc.org/3.4.1/Enumerable.html#method-i-grep) to pattern
+match on the type directly.
+
+```ruby
+> nums = [1, :two, 3.0, 'four', 5, -> { 6 }, 0.7]
+=> [1, :two, 3.0, "four", 5, #<Proc:0x0000000123af0338 (irb):5 (lambda)>, 0.7]
+> nums.filter { it.is_a?(Numeric) }
+=> [1, 3.0, 5, 0.7]
+> nums.filter { Integer === it }
+=> [1, 5]
+> nums.grep(Integer)
+=> [1, 5]
+> nums.grep(Numeric)
+=> [1, 3.0, 5, 0.7]
+```
+
+[source](https://bsky.app/profile/lucianghinda.com/post/3mhi5xp3xhk25)

ruby/load-a-module-and-execute-a-statement.md

@@ -0,0 +1,25 @@
+# Load A Module And Execute A Statement
+
+Here is a nice one-liner pattern for use with the `ruby` executable.
+
+```bash
+$ ruby -r file.rb -e 'MyClass.do_something'
+```
+
+The `-r` flag loads (requires, really) a Ruby file at the specified path. The
+`-e` flag will execute the line of Ruby code that you give it, in that context.
+In combination that means I can load some module into the execution environment
+and then I can run some code that uses that module.
+
+A more practical example of that is how I demonstrated the behavior of a
+`MarkdownHelpers` module in [Create A Module Of Utility
+Functions](create-a-module-of-utility-functions.md).
+
+```bash
+$ ruby -r ./markdown_helpers.rb -e 'puts MarkdownHelpers.link("Click here", "https://example.com")'
+[Click here](https://example.com)
+```
+
+The `MarkdownHelpers` module that I've defined in `./markdown_helpers.rb` is
+loaded into context and I can now access and execute that module to try out
+parts of it. All in a single line in the terminal.

ruby/make-a-long-string-of-text-readable.md

@@ -0,0 +1,38 @@
+# Make A Long String Of Text Readable
+
+I have a paragraph of text that interpolates a couple user-specific values
+before being included in an API request. Because it is being passed to an API,
+it is a single-line string value. However, in the editor it is hard to read like
+that because it overflows way past the edge of the viewport.
+
+```ruby
+description = "This is the description we need to provide for #{user.name} as part of an API request dealing with compliance and registration for a service. If you need to contact them, their email is #{user.email}."
+```
+
+I'd rather make this easier on myself and others to read from the editor while
+still being able to submit a single-line string to the API. That can be
+accomplished with a heredoc and some combination or `gsub`, `strip`, and
+`squish`.
+
+If we are in a strictly Ruby-only context, we can use `gsub` and `strip` to
+collapse line breaks and remove surrounding white space.
+
+```ruby
+description = <<~MSG.gsub(/\s+/, ' ').strip
+  This is the description we need to provide for #{user.name} as part
+  of an API request dealing with compliance and registration for a
+  service. If you need to contact them, their email is #{user.email}.
+MSG
+#=> "This is the description we need to provide for #{user.name} as part of an API request dealing with compliance and registration for a service. If you need to contact them, their email is #{user.email}."
+```
+
+Or in a Rails context, I can instead just use `squish`:
+
+```ruby
+description = <<~MSG.squish
+  This is the description we need to provide for #{user.name} as part
+  of an API request dealing with compliance and registration for a
+  service. If you need to contact them, their email is #{user.email}.
+MSG
+#=> "This is the description we need to provide for #{user.name} as part of an API request dealing with compliance and registration for a service. If you need to contact them, their email is #{user.email}."
+```

ruby/specify-default-for-data-definition.md

@@ -0,0 +1,43 @@
+# Specify Default For Data Definition
+
+Here is what a `Data` definition for the concept of a `Permission` might look
+like:
+
+```ruby
+Permission = Data.define(:id, :name, :description, :enabled)
+
+perm1 = Permission.new(
+  id: 123,
+  name: :can_edit,
+  description: "User is allowed to edit.",
+  enabled: true
+)
+```
+
+However, as we're creating various `Permission` entities, we may find that the
+vast majority of them are _enabled_ by default and so we'd like to apply `true`
+as a default value.
+
+We cannot do this directly in the `Data` definition, but we can open a block to
+override the `initialize` method.
+
+```ruby
+Permission = Data.define(:id, :name, :description, :enabled) do
+  def initialize(:id, :name, :description, enabled: true)
+    super
+  end
+end
+
+perm1 = Permission.new(
+  id: 123,
+  name: :can_edit,
+  description: "User is allowed to edit."
+)
+
+perm1.enabled #=> true
+```
+
+Now we're able to create a `Permission` without specifying the `enabled`
+attribute and it takes on the default of `true`.
+
+[source](https://dev.to/baweaver/new-in-ruby-32-datadefine-2819#comment-254o8)

taskfile/add-default-task-to-list-all-tasks.md

@@ -0,0 +1,52 @@
+# Add Default Task To List All Tasks
+
+One thing I like about [`just`](https://github.com/casey/just) is that if you
+run `just` by itself, the default behavior is to list out all the commands it
+can run.
+
+[Taskfile](https://github.com/go-task/task) technically does this as well, but
+with a warning at the end:
+
+```
+❯ task
+task: Available tasks for this project:
+* notes:              Interactive picker for notes tasks
+* notes:diff:         Show uncommitted changes in notes
+* notes:edit:         All-in-one edit, commit, and push notes
+* notes:log:          Show recent commit history for notes
+* notes:open:         Opens NOTES.md (syncs latest changes first) in default editor
+* notes:push:         Commit and push changes to notes submodule
+* notes:status:       Check status of notes submodule
+* notes:sync:         Sync latest changes from the notes submodule
+task: Task "default" does not exist
+```
+
+I prefer to tidy this up a little by adding `task --list` as the _default_ in my
+`Taskfile.yml`.
+
+```yml
+  default:
+    desc: Show available commands
+    cmds:
+      - task --list
+```
+
+Now when I run `task` with no arguments, I get this minutely nicer version:
+
+```
+❯ task
+Alias tip: t
+task: [default] task --list
+task: Available tasks for this project:
+* default:            Show available commands
+* notes:              Interactive picker for notes tasks
+* notes:diff:         Show uncommitted changes in notes
+* notes:edit:         All-in-one edit, commit, and push notes
+* notes:log:          Show recent commit history for notes
+* notes:open:         Opens NOTES.md (syncs latest changes first) in default editor
+* notes:push:         Commit and push changes to notes submodule
+* notes:status:       Check status of notes submodule
+* notes:sync:         Sync latest changes from the notes submodule
+```
+
+Notice there is no `task: Task "default" does not exist` warning at the end.

tmux/list-processes-running-across-all-sessions.md

@@ -0,0 +1,46 @@
+# List Processes Running Across All Session
+
+I wanted an overview of all the processes running across all the tmux sessions
+that I have running on my machine right now. The `list-panes` command (with the
+`-a` flag) gives me a listing of all the panes across all session of the current
+tmux server.
+
+That output on its own isn't giving me quite the info I'm looking for though.
+With the `-f` (_format_) flag, I can use variables available in that context
+like `session_name`, `pane_pid`, and `pane_current_command`.
+
+I can assemble the details I want into a command like this:
+
+```bash
+❯ tmux list-panes -a -F "#{session_name}:#{window_index}.#{pane_index} #{pane_pid} #{pane_current_command}"
+PLP:1.1 62364 zsh
+TIL:1.1 62345 nvim
+TIL:1.2 65838 task
+TIL:2.1 11428 tmux
+client-app:1.1 62373 ssh
+client-app:1.2 10796 zsh
+client-app:1.3 63081 zsh
+client-app:2.1 61115 overmind
+client-app:3.1 82608 zsh
+visualmode-dev:1.1 52237 zsh
+```
+
+This gives me the details I want, but I can take it a step further by piping it
+to the `column` command to improve the formatting a little:
+
+```bash
+❯ tmux list-panes -a -F "#{session_name}:#{window_index}.#{pane_index} #{pane_pid} #{pane_current_command}" \
+  | column -t
+PLP:1.1             62364  zsh
+TIL:1.1             62345  nvim
+TIL:1.2             65838  task
+TIL:2.1             11428  tmux
+client-app:1.1      62373  ssh
+client-app:1.2      10796  zsh
+client-app:1.3      63081  zsh
+client-app:2.1      61115  overmind
+client-app:3.1      82608  zsh
+visualmode-dev:1.1  52237  zsh
+```
+
+See `man tmux` and, in particular, the `FORMATS` section for more details.

unix/apply-successive-filters-to-lines-in-less.md

@@ -0,0 +1,33 @@
+# Apply Successive Filters To Lines In Less
+
+Let's say I've opened a large Rails log file with `less`:
+
+```bash
+$ less logs/development.log
+```
+
+I have an idea of what I'm looking for, but there is way more noise than signal.
+I can start to filter out some of the noise. The `&` command starts a filter
+prompt. If I start to filter by something like `INSERT INTO`, then a ton of
+lines disappear leaving just those matching that pattern.
+
+Scrolling through the current set of lines, I start to have a better idea of
+what I'm looking for, but there is still too much noise. I can apply an
+additional successive filter on the remaining lines by hitting `&` again and
+entering in another pattern -- e.g. `GoodJob`.
+
+Now I only see lines that contain both `INSERT INTO` and `GoodJob` somewhere in
+them.
+
+As `less` puts it:
+
+> Multiple & commands may be entered, in which case only lines which match all
+> of the patterns will be displayed.
+
+If I want to undo all the filtering, I just need to enter an empty `&` filter
+prompt and it will reset things back to displaying all lines.
+
+> If pattern is empty (if you type & immediately followed by ENTER), any
+> filtering is turned off, and all lines are displayed.
+
+See `man less` for more details.

unix/browse-and-search-help-docs.md

@@ -0,0 +1,22 @@
+# Browse And Search Help Docs
+
+There are a lot of tools that don't have dedicated `man` pages, but do have
+lengthy output when you pass them the `--help` flag.
+
+We can make those details easier to browse and searchable by piping them to
+`less`.
+
+```bash
+❯ uv run pytest --help | less
+```
+
+First, we see the top of the output inside `less` instead of bottom of the
+output right above our next terminal prompt.
+
+From `less`, we can use down and up arrows (or `j` and `k`) to navigate through
+the details. We can also jump to a specific word or phrase by searching -- type
+`/` and then the pattern we're trying to match. `n` and `N` to go to the next or
+previous match, respectively.
+
+See `man less` more more details. And if you like these improvements to viewing
+tool usage details, you may also be interested in [a better man page viewer](https://www.visualmode.dev/a-better-man-page-viewer).

unix/combine-all-my-tils-into-a-single-file.md

@@ -0,0 +1,35 @@
+# Combine All My TILs Into A Single File
+
+In [Build A Small Text-based Training
+Dataset](https://www.visualmode.dev/build-a-small-text-training-dataset), I went
+over my need for a sizeable and interesting corpus of text that I could use as a
+training dataset I could use to run against [my own naive Byte Pair Encoding
+implementation](https://github.com/jbranchaud/build-an-llm-from-scratch/blob/main/chapter-02/bpe_tokenizer.py).
+My repo of hand-written TILs is a great candidate, but I need those smashed all
+into one file.
+
+Here is a formatted version of the one-liner I ended up with:
+
+```bash
+{
+  cat README.md; \
+  find */ -name '*.md' -print0 \
+  | sort -z \
+  | xargs -0 -I{} sh -c 'echo "<|endoftext|>"; cat "$1"' _ {}; \
+} > combined.md
+```
+
+This combines all 1700+ of my TILs into a single file separated by the
+`<|endoftext|>` delimiter.
+
+The two things I find most interesting about this command are:
+
+1. The use of a null byte (`\0`) separator between the filenames in case there
+   is anything weird (like spaces) in those filenames. This starts with
+   `-print0`. The `-z` of `sort` maintains that null byte separator. And then
+   `xargs` knows to handle it by the `-0` flag.
+
+2. We can coerce `xargs` into running multiple commands by having it spawn a
+   single shell process that runs each of those commands. To reliably pass the
+   filename into that shell process, we have `xargs` constitute it as the second
+   argument (`$1`) by substituting in the filename where `{}` appears.

unix/diff-two-files-in-unified-format.md

@@ -0,0 +1,78 @@
+# Diff Two Files In Unified Format
+
+The `diff` command is a standalone utility that can be used to get the
+difference between two files. It is similar to what you might expect when
+running `git diff` which compares two different versions of the same file. The
+`diff` command predates `git` and its unified format is what became the standard
+that `git` uses for its own diff implementation.
+
+Running `diff` with two files as is gives output like the following:
+
+```bash
+❯ diff startup.sh startup2.sh
+10,13c10,14
+< declare -A SESSIONS=(
+<   ["TIL"]="$HOME/dev/jbranchaud/til:setup_til"
+<   ["PLP"]="$HOME/dev/jbranchaud/pool-league-pro:"
+<   ["client-app"]="$HOME/dev/client/client-app:"
+---
+> # Sessions will be created in the order listed here
+> SESSIONS=(
+>   "TIL:$HOME/dev/jbranchaud/til:setup_til"
+>   "PLP:$HOME/dev/jbranchaud/pool-league-pro:"
+>   "client-app:$HOME/dev/client/client-app:"
+73,74c74,75
+<   for session_name in TIL PLP client-app; do
+<     IFS=':' read -r directory setup_function <<<"${SESSIONS[$session_name]}"
+---
+>   for session_config in "${SESSIONS[@]}"; do
+>     IFS=':' read -r session_name directory setup_function <<<"$session_config"
+```
+
+That's readable at a glance, but the unified format (with the `-u` flag) can
+provide more context:
+
+```bash
+❯ diff -u startup.sh startup2.sh
+--- startup.sh  2026-01-10 12:46:52
++++ startup2.sh 2026-01-10 12:48:00
+@@ -7,10 +7,11 @@
+
+ # Session configurations
+ # Format: "session_name:directory:setup_function"
+-declare -A SESSIONS=(
+-  ["TIL"]="$HOME/dev/jbranchaud/til:setup_til"
+-  ["PLP"]="$HOME/dev/jbranchaud/pool-league-pro:"
+-  ["client-app"]="$HOME/dev/client/client-app:"
++# Sessions will be created in the order listed here
++SESSIONS=(
++  "TIL:$HOME/dev/jbranchaud/til:setup_til"
++  "PLP:$HOME/dev/jbranchaud/pool-league-pro:"
++  "client-app:$HOME/dev/client/client-app:"
+ )
+
+ # Setup function for TIL session
+@@ -70,8 +71,8 @@
+   echo ""
+
+   # Create sessions in order
+-  for session_name in TIL PLP client-app; do
+-    IFS=':' read -r directory setup_function <<<"${SESSIONS[$session_name]}"
++  for session_config in "${SESSIONS[@]}"; do
++    IFS=':' read -r session_name directory setup_function <<<"$session_config"
+     create_session "$session_name" "$directory" "$setup_function"
+   done
+```
+
+Here we get additional context like surrounding lines and file name details.
+
+While this is useful on its own, it also has the added benefit of making the
+output compatible with other tools we may already be using. For instance, I'm
+already using [delta](https://github.com/dandavison/delta) as my [git pager](https://github.com/jbranchaud/dotfiles/blob/main/gitconfig#L51) and [git differ](https://github.com/jbranchaud/dotfiles/blob/main/gitconfig#L139).
+
+With the unified format, I can pipe the output directly to `delta` to get a
+better view of the diff that is colorized and includes syntax highlighting.
+
+```bash
+❯ diff -u startup.sh startup2.sh | delta
+```

unix/display-line-numbers-while-using-less.md

@@ -0,0 +1,27 @@
+# Display Line Numbers While Using Less
+
+Including line numbers while viewing files with `less` can provide useful
+context for understanding where you are within the file. This is especially true
+if you've used `&` to filter down to lines that match a pattern.
+
+You can start `less` with line numbers with the `-N` flag (or `--LINE-NUMBERS`
+if you really want to spell it out).
+
+```bash
+$ less -N log/development.log
+```
+
+If you've already started up `less` and wish you had included line numbers,
+there is no reason to restart it with the flag. Instead, toggle the line numbers
+option on within the `less` process. To do this, type `-N`. It will prompt you
+with `Constantly display line numbers (press RETURN)`. Hit enter and line
+numbers will appear to the left of each line in the file.
+
+Similarly, to toggle line numbers back off within `less`, hit `-n` (lower-case
+`n`), accept the prompt, and back off they go.
+
+Both of these (`-N`/`-n`) are options being set (toggled) via the `-` command.
+There are many other options like these that can be configured within a `less`
+session in the same way.
+
+See `man less` and find the `-` command and the available `OPTIONS`.

unix/format-and-display-small-amounts-of-columnar-data.md

@@ -0,0 +1,44 @@
+# Format And Display Small Amounts Of Columnar Data
+
+In [_List Processes Running Across All (tmux)
+Sessions](tmux/list-processes-running-across-all-sessions.md), I showed an
+example of piping some data from `tmux` to the `column -t` command to nicely format
+and display the columnar data as a table. By default is uses spaces as the
+delimiter.
+
+```bash
+❯ tmux list-panes -a -F "#{session_name}:#{window_index}.#{pane_index} #{pane_pid} #{pane_current_command}" \
+  | column -t
+
+PLP:1.1             62364  zsh
+TIL:1.1             62345  nvim
+TIL:1.2             65838  task
+TIL:2.1             11428  tmux
+client-app:1.1      62373  ssh
+client-app:1.2      10796  zsh
+client-app:1.3      63081  zsh
+client-app:2.1      61115  overmind
+client-app:3.1      82608  zsh
+visualmode-dev:1.1  52237  zsh
+```
+
+This can be useful for formatting data from all kinds of commands and tools.
+Sometimes the columns of data are separated by something other than spaces. For
+instance, here is some git branch information (for my [dotfiles
+repo](https://github.com/jbranchaud/dotfiles)) separated by the `|` character.
+To format that with `column`, I need to also include the `-s '|'` flag to
+override the delimiter.
+
+```bash
+❯ git for-each-ref --format='%(refname:short)|%(authordate:short)|%(authorname)' refs/heads/ \
+  | column -t -s '|'
+
+claude/sync-dotfiles-011CUP87cRV6c51eEi3Chg99  2025-10-22  jbranchaud
+jb/add-rhubarb-for-fugitive-github-browse      2025-11-02  jbranchaud
+jb/fix-hardcoded-paths                         2025-11-02  jbranchaud
+jb/set-nvim-to-default-manpager                2025-10-19  jbranchaud
+main                                           2026-01-10  jbranchaud
+master                                         2025-10-30  Dorian Karter
+my-dotfiles                                    2025-11-01  jbranchaud
+upstream-master                                2026-01-01  Dorian Karter
+```

unix/inspect-exif-data-for-an-image-file.md

@@ -0,0 +1,47 @@
+# Inspect EXIF Data For An Image File
+
+The `exiftool` CLI (which can be downloaded via `brew`) is a useful tool for
+inspecting all the EXIF data attached to a media file. A media file like an
+image has a bunch of additional details embedded in it like timestamps, image
+metadata, and sometimes location information.
+
+Here is all the data attached to a screenshot I found on my desktop:
+
+```bash
+❯ exiftool ~/Desktop/CleanShot\ 2025-11-17\ at\ 11.22.18@2x.png
+ExifTool Version Number         : 13.50
+File Name                       : CleanShot 2025-11-17 at 11.22.18@2x.png
+Directory                       : /Users/lastword/Desktop
+File Size                       : 1194 kB
+File Modification Date/Time     : 2025:11:17 11:22:21-06:00
+File Access Date/Time           : 2025:12:15 10:43:55-06:00
+File Inode Change Date/Time     : 2025:12:05 15:37:48-06:00
+File Permissions                : -rw-r--r--
+File Type                       : PNG
+File Type Extension             : png
+MIME Type                       : image/png
+Image Width                     : 2502
+Image Height                    : 1232
+Bit Depth                       : 8
+Color Type                      : RGB with Alpha
+Compression                     : Deflate/Inflate
+Filter                          : Adaptive
+Interlace                       : Noninterlaced
+XMP Toolkit                     : XMP Core 6.0.0
+Y Resolution                    : 144
+Resolution Unit                 : inches
+X Resolution                    : 144
+Exif Image Width                : 2502
+Color Space                     : sRGB
+User Comment                    : Screenshot
+Exif Image Height               : 1232
+SRGB Rendering                  : Perceptual
+Image Size                      : 2502x1232
+Megapixels                      : 3.1
+```
+
+This works with other kinds of media files. For instance, I ran this against an
+MP4 screen recording file which contained even more metadata.
+
+In addition to reading data, `exiftool` can also write it. See `man exiftool`
+for more details on what else it can do.

unix/reverse-each-line-of-a-file.md

@@ -0,0 +1,64 @@
+# Reverse Each Line Of A File
+
+The [`rev` command](https://man7.org/linux/man-pages/man1/rev.1.html) can be
+used to reverse each line in a file. Every line is left where it is relative to
+other lines, but the contents of each line is reversed.
+
+So a file that contains the following text:
+
+```bash
+❯ cat stuff.md
+Three
+Two
+One
+go racecar go
+```
+
+can be piped to `rev` to get the following output:
+
+```bash
+❯ rev stuff.md
+eerhT
+owT
+enO
+og racecar og
+```
+
+This is an odd utility that doesn't have too much use that I can imagine. After
+a brief chat with Claude where I asked for some practical use cases, the one
+that stood out the most to me is to reverse a list of filenames, sort them, and
+then reverse them again (putting them back in readable order). This can shuffle
+filenames with similar endings near each other like source and test files.
+
+Here is a list of files for me [`py-vmt`
+project](https://github.com/jbranchaud/py-vmt):
+
+```bash
+❯ fd -t f .
+README.md
+pyproject.toml
+src/py_vmt/__init__.py
+src/py_vmt/cli.py
+src/py_vmt/session.py
+src/py_vmt/time_helpers.py
+tests/src/py_vmt/test_cli.py
+tests/src/py_vmt/test_session.py
+```
+
+Now I can pipe the output of that `fd` command through `rev | sort | rev` to get
+my files organized in a different way.
+
+```bash
+❯ fd -t f . | rev | sort | rev
+README.md
+pyproject.toml
+src/py_vmt/__init__.py
+tests/src/py_vmt/test_cli.py
+src/py_vmt/cli.py
+tests/src/py_vmt/test_session.py
+src/py_vmt/session.py
+src/py_vmt/time_helpers.py
+```
+
+Again the value of doing something like this is a bit tenuous. At the very least
+it is fun to know about.

unix/show-tree-view-of-processes-and-subprocesses.md

@@ -0,0 +1,36 @@
+# Show Tree View Of Processes And Subprocesses
+
+Though you can cobble together a command on a MacOS Unix system to output a
+hierarchical tree view of a parent process and its descendent subprocesses, it
+is easier to [`brew install pstree`](https://github.com/FredHucht/pstree) and
+use that.
+
+Here is what I see when I run it for a _pid_ that corresponds to a `tmux`
+session that I have running locally:
+
+```bash
+❯ pstree 61690
+-+= 61690 lastword tmux new-session -d -s TIL -c /Users/lastword/dev/jbranchaud/til
+ |--= 63081 lastword /bin/zsh
+ |-+= 11428 lastword zsh
+ | \-+= 48511 lastword pstree 61690
+ |   \--- 48512 root ps -axwwo user,pid,ppid,pgid,command
+ |-+= 62345 lastword zsh
+ | \--= 06031 lastword claude
+ |--= 62364 lastword /bin/zsh
+ |-+= 62373 lastword zsh
+ | \--= 64407 lastword ssh my-app-staging
+ |-+= 61115 lastword /bin/zsh
+ | \-+= 61579 lastword overmind start -f Procfile.dev
+ |   \--- 61586 lastword tmux -C -L overmind-my-app-abc123 new -n web -s my-app -P -F %overmind-process #{pane_id} web #{pane_pid} /var/folders/zc/abc123/T/overmin
+ |--= 52237 lastword /bin/zsh
+ |--= 82608 lastword /bin/zsh
+ \--= 10796 lastword /bin/zsh
+```
+
+I was looking for a frozen `claude` process that was part of this session. And I
+found it about halfway down that list -- `06031`. Now I can run `kill` on that
+process as needed.
+
+For some additional context, I initially found the _pid_ for the `tmux` session
+by running `ps aux | grep tmux` and looking through those results.

unix/use-negative-lookbehind-matching-with-ripgrep.md

@@ -0,0 +1,42 @@
+# Use Negative Lookbehind Matching With ripgrep
+
+The most straightforward way to use `ripgrep` is to hand it a pattern. It will
+take that pattern and move forward through each file trying to find matches.
+
+```bash
+$ rg 'TwilioClient\.new'
+```
+
+That will find all occurrences of `TwilioClient.new` in available project files.
+
+What if that pattern is too permissive though? That is going to match on
+occurrences of `TwilioClient.new` as well as things like
+`LoggingTwilioClient.new`. If we want to exclude the latter, there are a few
+ways to do that. One of them being the use of [the _negative lookbehind_ regex
+feature](https://www.pcre.org/current/doc/html/pcre2syntax.html#SEC23) that is
+available with PCRE2 (Perl-Compatible Regular Expressions).
+
+A _negative lookbehind_ is like a standard pattern. We look forward through the
+document for the base pattern (like `TwilioClient\.new`). However, once we find
+that match, we then look back at the previous characters and if they match our
+negative lookbehind pattern, then it is no longer a positive match.
+
+We can use one of the following to forms to achieve this:
+
+```
+  (?<!...)                    )
+  (*nlb:...)                  ) negative lookbehind
+  (*negative_lookbehind:...)  )
+```
+
+For instance, here is what this looks like for our example:
+
+```bash
+$ rg -P '(?<!Logging)TwilioClient\.new'
+```
+
+Note: we have to use the `-P` flag to tell `ripgrep` that we are using PCRE2
+syntax. Otherwise, it assumes a simpler regex syntax that doesn't support
+_negative lookbehind_.
+
+See `man rg` for more details.

unix/use-the-readline-keybindings-anywhere.md

@@ -0,0 +1,30 @@
+# Use The Readline Keybindings Anywhere
+
+There are these features of the "shell" that I've often heard called _emac
+keybindings_. These are things like `ctrl-a` (move the cursor to the beginning
+of the line) and `ctrl-e` (move the cursor to the end of the line) that I use
+every single day. There are several others that are in my heavy rotation,
+however, I learned about a couple more reading through [Shell Tricks That
+Actually Make Life Easier (And Save Your
+Sanity)](https://blog.hofstede.it/shell-tricks-that-actually-make-life-easier-and-save-your-sanity/).
+
+These are [Readline commands](https://www.gnu.org/software/bash/manual/html_node/Bindable-Readline-Commands.html)
+(or keybindings) which means they are supported by anything that uses Readline
+under the hood. So while you might be using these to great effect in `bash` and
+`zsh`, you should look for other places they are available.
+
+A non-exhaustive list includes:
+
+- Ruby's `irb`
+- Python's `python`
+- Node.js' `node`
+- PostgreSQL's `psql`
+- Claude Code
+
+And many more similar REPLs and command line tools.
+
+Try these keybindings out in one of your favorites and when you're done hit
+`ctrl-c` to exit out of it.
+
+PS. subsets of these keybindings are sometimes supported in unexpected places
+like the Chrome URL bar.

workflow/view-nicely-formatted-markdown-from-terminal.md

@@ -0,0 +1,40 @@
+# View Nicely Formatted Markdown From Terminal
+
+The [`glow`](https://github.com/charmbracelet/glow) utility is CLI markdown
+renderer written in Go. It is part of the CCU
+([charmbraclet](https://github.com/charmbracelet) CLI universe). And yes, I just
+made up _CCU_.
+
+`glow` is great because it processes and outputs a markdown file with some
+styling tailored to a terminal including:
+
+- colors to emphasize things like headings
+- styling of inline code snippets
+- syntax highlighting for fenced code blocks
+- rendering of markdown tables
+- and a lot more that I'm not thinking to mention
+
+In the past I've installed this with `brew`, but I currently manage my `glow`
+install with [this mise config](https://github.com/jbranchaud/dotfiles/blob/main/config/mise/config.toml?plain=1#L66).
+
+To view a nicely rendered markdown file, I can run:
+
+```bash
+$ glow README.md
+```
+
+For long markdown files like [this `README.md`](https://github.com/jbranchaud/til/blob/master/README.md), this
+doesn't work too well because it renders until the end and spits you at at the
+bottom.
+
+Fortunately, `glow` has a built-in pager that maintains all the styling while
+allowing you to navigate and search similar to `less`.
+
+```bash
+$ glow -p README.md
+```
+
+There is also a TUI version (`-t`), but I find that less intuitive and useful
+than the pager.
+
+See `glow --help` for more details.

zsh/list-available-zle-keybindings.md

@@ -0,0 +1,44 @@
+# List Available Zle Keybindings
+
+Unlike `bash` which uses `readline`, `zsh` has its own implementation of a line
+editing library -- `zle`. A lot of the core bindings between the two are the
+same, e.g. `Ctrl-a` and `Ctrl-e` to go the beginning and end of the command line
+prompt, respectively.
+
+All available `zle` keybindings can be listed out by running `bindkey` without
+any arguments.
+
+The best way to check out an unaltered version of this list is by starting a
+fresh `zsh` process with no RCS files loaded in. The `-f` flag does that. Note
+though that when `zsh` is starting fresh, it has to decide whether to start in
+_Emacs_ mode or _Vi_ mode. If it sees that your default editor is something like
+`vi`, `vim` or `nvim`, then it will start you in _Vi_ mode.
+
+Starting in _Vi_ mode can be confusing because none of the standard _Emacs_
+keybindings like `Ctrl-a` and `Ctrl-e` are available in that context. So first
+ensure you're in _Emacs_ mode by running:
+
+```sh
+❯ zsh -f
+lastword% bindkey -e
+```
+
+Now you can list out all the keybindings:
+
+```sh
+lastword% bindkey
+"^@" set-mark-command
+"^A" beginning-of-line
+"^B" backward-char
+"^D" delete-char-or-list
+"^E" end-of-line
+"^F" forward-char
+"^G" send-break
+"^H" backward-delete-char
+"^I" expand-or-complete
+"^J" accept-line
+"^K" kill-line
+...
+```
+
+See `man zshzle` for more details on `zle` and `bindkey`.