[issue34284] Nonsensical exception message when calling `__new__` on some sys objects

[Vadim Pushtaev]

Vadim Pushtaev <pushtaev.vm at gmail.com> added the comment:

Here is what I learned:

1) Nothing is wrong with that "tuple.__new__(sys.flags) is not safe" part. `__new__` is deleted from `type(sys.flags)`, so parent's `__new__` is called. `tuple` is indeed a base class for `type(sys.flags)`.

2) Another part where we recommend to use "sys.flags.__new__()" doesn't make much sense, so I choose to delete this advice if there is no `__new__` in a class.

3) This second part also may suggest a wrong class to call `__new__` from:


In [1]: from collections import namedtuple

In [2]: class A(namedtuple('A', 'z')):
   ...:     pass
   ...:

In [3]: object.__new__(A)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-3-24eacd9ea752> in <module>()
----> 1 object.__new__(A)

TypeError: object.__new__(A) is not safe, use tuple.__new__()


This should be A.__new__(), not tuple.__new__().

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue34284>
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