Issue 35357: unittest.mock.call can't represent calls to a method called 'parent'

While working on https://bugs.python.org/issue35226, I stumbled upon this:

>>> from unittest.mock import call
>>> call.parent()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'NoneType' object is not callable

Guess we need to make .parent and friends more uniquely named ;-)

I've just stumbled upon this issue while looking for a good first issue to contribute on. If the community agrees this is something that needs to be done, I'll gladly work on this.

Go for it! :-)

I see 2 most applicable ways to do it:

- Hide .parent and .name by mangling
- Define them within the mock class definition scope, but not within the class itself.

As long as those are accessed only from within the mock class, I think second method would be better as it would completely remove them from mock's attributes.

Not sure I follow the second option, I was thinking of just _mock_parent and _mock_name when I logged this.

Happy to see a PR for either though!

I was considering wrapping a `unittest.mock._Call` class definition within a function that would contain name & parent as local variables (arguments). Thus they would be accessible within the `_Call` class, but wouldn't be accessible from the outside. However this would make them inaccessible from other instances of `_Call`. So I think I'll stick to the more trivial solution of renaming them to `_mock_name` and `_mock_parent` to conform to the rest of the module :)

New changeset e63e617ebbe481c498bdf037a62e09f4f9f3963f by Chris Withers (Andrew Dunai) in branch 'master':
bpo-35357: Add _mock_ prefix to name/parent/from_kall attributes of _Call/_MagicProxy. (#10873)
https://github.com/python/cpython/commit/e63e617ebbe481c498bdf037a62e09f4f9f3963f

New changeset 12735c14134082584b899308af8dd8fcc9f15696 by Chris Withers (Miss Islington (bot)) in branch '3.7':
bpo-35357: Add _mock_ prefix to name/parent/from_kall attributes of _Call/_MagicProxy. (GH-10873) (#10887)
https://github.com/python/cpython/commit/12735c14134082584b899308af8dd8fcc9f15696

New changeset 70ca3fce9fe2bdd7bf97d5fe1299cfa5e32b3ad4 by Chris Withers (Miss Islington (bot)) in branch '3.6':
bpo-35357: Add _mock_ prefix to name/parent/from_kall attributes of _Call/_MagicProxy. (GH-10873)
https://github.com/python/cpython/commit/70ca3fce9fe2bdd7bf97d5fe1299cfa5e32b3ad4