inspect.getmembers will call the instance __bases__ attribute, which may cause an exception

[hongweipeng]

BPO	46103
Nosy	@terryjreedy, @pitrou, @ethanfurman, @1st1, @hongweipeng
PRs	bpo-46103: Fix inspect.getmembers call the instance __bases__ attribute which ma… #30147

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-12-16.15:40:43.879>
labels = ['type-bug', 'library', '3.11']
title = 'inspect.getmembers will call the instance __bases__ attribute, which may cause an exception'
updated_at = <Date 2022-01-23.17:40:42.489>
user = 'https://github.com/hongweipeng'

bugs.python.org fields:

activity = <Date 2022-01-23.17:40:42.489>
actor = 'ethan.furman'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2021-12-16.15:40:43.879>
creator = 'hongweipeng'
dependencies = []
files = []
hgrepos = []
issue_num = 46103
keywords = ['patch']
message_count = 3.0
messages = ['408717', '408827', '411389']
nosy_count = 6.0
nosy_names = ['ping', 'terry.reedy', 'pitrou', 'ethan.furman', 'yselivanov', 'hongweipeng']
pr_nums = ['30147']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue46103'
versions = ['Python 3.11']

[hongweipeng]

root@debian:/workspace/cpython# ./python
Python 3.11.0a3+ (heads/main-dirty:b123ad8030, Dec 16 2021, 06:16:15) [GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import inspect
>>> class Foo:
...   def __getattr__(self, attr):
...     return None
... 
>>> inspect.getmembers(Foo())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/workspace/cpython/Lib/inspect.py", line 488, in getmembers
    return _getmembers(object, predicate, getattr)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/workspace/cpython/Lib/inspect.py", line 455, in _getmembers
    for base in object.__bases__:
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not iterable

[terryjreedy]

PR edits inspect._getmembers. I nosied people who have edited it previously.

[ethanfurman]

New changeset 691506f by Weipeng Hong in branch 'main':
bpo-46103: Fix inspect.getmembers to only get __bases__ from class (GH-30147)
691506f

[erlend-aasland]

Fixed with gh-30147.