[Python-bugs-list] [ python-Bugs-718532 ] inspect, class instances and __getattr__

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Bugs item #718532, was opened at 2003-04-09 22:01
Message generated for change (Tracker Item Submitted) made by Item Submitter
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https://sourceforge.net/tracker/?func=detail&atid=105470&aid=718532&group_id=5470

Category: Python Library
Group: Python 2.2.2
Status: Open
Resolution: None
Priority: 5
Submitted By: Stefan Schwarzer (sschwarzer)
Assigned to: Nobody/Anonymous (nobody)
Summary: inspect, class instances and __getattr__

Initial Comment:
inspect.isclass(class_instance) fails if the
corresponding class uses a "wildcard" implementation of
__getattr__.

Example:

Python 2.2.2 (#1, Nov 13 2002, 22:53:57) 
[GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
Type "help", "copyright", "credits" or "license" for
more information.
>>> import inspect
>>> class X:
...     def __getattr__(self, name):
...             if name == 'foo':
...                     return 1   
...             if name == 'bar':
...                     return 2
...             else:
...                     return "default"
... 
>>> x = X()
>>> inspect.isclass(x)
1

The problematic expression in inspect.isclass is
hasattr(object, '__bases__') which returns a true value.

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