Add Dunder Methods as a Python TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1504 TILs and counting..._
+_1505 TILs and counting..._
 
 ---
 
@@ -887,6 +887,7 @@ _1504 TILs and counting..._
 
 - [Access Instance Variables](python/access-instance-variables.md)
 - [Create A Dummy DataFrame In Pandas](python/create-a-dummy-dataframe-in-pandas.md)
+- [Dunder Methods](python/dunder-methods.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)

python/dunder-methods.md

@@ -0,0 +1,22 @@
+# Dunder Methods
+
+Python has all kinds of special, or rather, _magic_ methods that allow for
+customizing all kinds of class behavior. There is `__init__()`, `__bool__()`,
+and so many others.
+
+The thing they all have in common is that their names are wrapped in _double
+underscores_. This is why they are called _dunder methods_.
+
+Some of these are used every single day, like the `__init__()` method for
+defining how a class should create an object. Others, used from time to time,
+are for overriding how comparisons or conversions happen. E.g. you may want to
+override `__bool__()` or `__len__()` to customize the truthiness of a custom
+class.
+
+There are so many others, ones you probably haven't even heard of. To see a
+full listing, check out this [cheat sheet of every dunder
+method](https://www.pythonmorsels.com/every-dunder-method/#cheat-sheet).
+
+Note: these are not to be confused with _dunder attributes_ which are things
+like `__name__`, `__file__`, and `__version__` which correspond to a value that
+you can access in a specific context rather than behavior to override.