New submission from Douglas Raillard <douglas.raill...@arm.com>: When creating a namedtuple such as this one:
from collections import namedtuple class C(namedtuple('C', ('hello', 'world'))): pass print(C.__new__.__globals__) The globals' dict of __new__ contains a "__builtins__" key which is set to None in collections/__init__.py: namespace = { '_tuple_new': tuple_new, '__builtins__': None, '__name__': f'namedtuple_{typename}', } When such globals are used with eval(), it will raise a TypeError such as: >>> eval('X', {'__builtins__': None}) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<string>", line 1, in <module> TypeError: 'NoneType' object is not subscriptable If an empty dict was used instead, we get the expected exception: >>> eval('X', {'__builtins__': {}}) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<string>", line 1, in <module> NameError: name 'X' is not defined Given that both ways allow preventing references to any builtin, please consider switching to an empty dict. Also, even though this is documented as implementation detail, this would agree more with the current documentation stating: The value of __builtins__ is normally either this module or the value of this module’s __dict__ attribute https://docs.python.org/3/library/builtins.html ---------- components: Library (Lib) messages: 386145 nosy: douglas-raillard-arm priority: normal severity: normal status: open title: namedtuple's __new__.__globals__['__builtins__'] is None type: behavior versions: Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue43102> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com