New submission from Benjamin Wohlwend:
The first descriptor example in the descriptor docs
(https://docs.python.org/3/howto/descriptor.html#descriptor-example) stores the
value on the descriptor instance, which is shared among all MyClass instances.
This leads to surprising (and arguably buggy from a user perspective) behaviour:
m1, m2 = MyClass(), MyClass()
m1.x = 5
m2.x = 10
print(m1.x, m2.x)
>>> 10 10
I'm not sure how this could be fixed without making the example much more
complicated (e.g. by introducing a "values" weakref dictionary on the
descriptor instance).
Maybe pointing this behaviour out in the docs could be enough, although I don't
see any useful use case for a class that has this behaviour.
----------
assignee: docs@python
components: Documentation
messages: 302033
nosy: Benjamin Wohlwend, docs@python
priority: normal
severity: normal
status: open
title: Descriptor example in documentation is confusing, possibly wrong
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Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue31441>
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