Add Reclassify Certain Packagaes As Dev Dependencies as a Python TIL

README.md

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@@ -1072,6 +1072,7 @@ If you've learned something here, support my efforts writing daily TILs by
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 - [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)

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.