Inaccurate emulation of _PyType_Lookup() in the Descriptor HOWTO #95822
Description
Documentation
Doc link: https://docs.python.org/3.10/howto/descriptor.html#invocation-from-an-instance
The code example is bad at https://github.com/python/cpython/blame/eb81c1aea16914347919745e843c982ed831a9fb/Doc/howto/descriptor.rst#L589
getattr(objtype, name) will go through descriptor.__get__.
Code Snippet:
class A: def __get__(self, obj, objtype): return obj, objtype class B: a = A() print(B().a) # (<__main__.B object at 0x7ff56d0915e0>, <class '__main__.B'>) print(B.a) # same as getattr # (None, <class '__main__.B'>)Solution
Using __dict__ (or vars) instead of getattr:
print(vars(B)['a']) # <__main__.A object at 0x7ff56cfef2b0>