Merge 5615da920f into 543a82730d

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).
 
-_1510 TILs and counting..._
+_1509 TILs and counting..._
 
 ---
 
@@ -888,7 +888,6 @@ _1510 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)
-- [Override The Boolean Context Of A Class](python/override-the-boolean-context-of-a-class.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/override-the-boolean-context-of-a-class.md

@@ -1,86 +0,0 @@
-# Override The Boolean Context Of A Class
-
-Everything in Python has a truthiness that can be checked with `bool()`. An
-empty list (`[]`) is falsy. A non-empty list (`[1,2,3]`) is truthy. Similar
-with numbers:
-
-```python
->>> bool(0)
-False
->>> bool(1)
-True
-```
-
-Any instance of an object is going to be truthy by default. If you want to
-control in what context an instance is considered truthy or falsy, you can
-override
-[`__bool__()`](https://docs.python.org/3/reference/datamodel.html#object.__bool__).
-If that's not implemented, but
-[`__len__()`](https://docs.python.org/3/reference/datamodel.html#object.__len__)
-is, then it will fallback to that.
-
-Let's look at a few example classes:
-
-```python
-class CartZero:
-    def __init__(self, items=[]):
-        self.items = items or []
-
-class CartBool:
-    def __init__(self, items=[]):
-        self.items = items or []
-
-    def __bool__(self):
-        print("__bool__() override")
-        return bool(self.items)
-
-class CartLen:
-    def __init__(self, items=[]):
-        self.items = items or []
-
-    def __len__(self):
-        print("__len__() override")
-        return len(self.items)
-
-class CartBoolAndLen:
-    def __init__(self, items=[]):
-        self.items = items or []
-
-    def __len__(self):
-        print("__len__() override")
-        return len(self.items)
-
-    def __bool__(self):
-        print("__bool__() override")
-        return bool(self.items)
-
-cart1 = CartZero()
-cart2 = CartBool()
-cart3 = CartLen()
-cart4 = CartBoolAndLen()
-
-print("CartZero() -> %s" %(bool(cart1)))
-print('')
-print("CartBool() -> %s" %(bool(cart2)))
-print('')
-print("CartLen() -> %s" %(bool(cart3)))
-print('')
-print("CartBoolAndLen() -> %s" %(bool(cart4)))
-```
-
-An 'empty' `Cart` be default is truthy. However, we can override some
-combination of `__bool__()` or `__len__()` to give it a boolean context that
-goes `false` when "empty".
-
-```
-CartZero() -> True
-
-__bool__() override
-CartBool() -> False
-
-__len__() override
-CartLen() -> False
-
-__bool__() override
-CartBoolAndLen() -> False
-```