[3.12] gh-88531 Fix dataclass __post_init__/__init__ interplay documentation (gh...

* Simplify __post_init__ example usage. It applies to all base classes, not just dataclasses.
(cherry picked from commit 05008c27b73da640b63c0d335c65ade517c0eb84)

Co-authored-by: Steffen Zeile <48187781+Kaniee@users.noreply.github.com>

diff --git a/Doc/library/dataclasses.rst b/Doc/library/dataclasses.rst
index 1b2f6d454dab65b755244fc35e537bd44fbc971d..020818a0812f0c948b2713bb1880690d750f9624 100644 (file)
--- a/Doc/library/dataclasses.rst
+++ b/Doc/library/dataclasses.rst
@@ -534,10 +534,10 @@ class :meth:`~object.__init__` methods. If the base class has an :meth:`~object.
 that has to be called, it is common to call this method in a
 :meth:`__post_init__` method::
 
-    @dataclass
     class Rectangle:
-        height: float
-        width: float
+        def __init__(self, height, width):
+          self.height = height
+          self.width = width
 
     @dataclass
     class Square(Rectangle):