Fixes#1961.
I mostly just replaced all str annotations with Text, including in return types. This is
only broadly correct; diffing a str and a unicode sequence actually results in a mixed
output of str and unicode. We could also keep the return types as str if using Text
causes errors in real code. For callbacks that take str, I introduced a Union alias
because a callable taking a str would not be a compatible with a parameter of type
Callable[[Text], bool].
I also fixed the return type of difflib.restore.
add_argument's type argument was recently changed to be (approximately)
`Callable[[_Text], _T]`. Because of contravariant subtyping for functions,
this had the effect of requiring that add_argument *always*
be unicode, which is wrong.
Change it to be `Callable[[str], _T]`.
This fixes an error in Travis that seems to have been caused by python/mypy#4319.
The fix was taken from the stdlib/3.4/enum.pyi stub. Mypy no longer assumes
that classes whose metaclass is EnumMeta are subclasses of Enum, so we can't
bound the typevar on Enum.
* Add _AttributeHolder and _ActionsContainer classes to argparse.
* Add Action subclasses to argparse.
* Add _UNRECOGNIZED_ARGS_ATTR, _ensure_value, _get_action_name to argparse.
* Fill in remaining _ActionsContainer attributes.
* Fill in missing argparse.ArgumentParser attributes.
* Fill in missing argparse.HelpFormatter attributes.
* Fill in remaining missing attributes on argparse classes.
* Rename TypeVar _ActionVar to _ActionT
* Add a version check for FileType attributes
* Add '# undocumented' where appropriate
* Add more # undocumented comments
* Make arguments to _ActionsContainer.add_argument more precise.
As promised in #2014.
There are virtually no real changes between Python 2 and 3 in this module, but the stub had accumulated some meaningless differences. I also fixed a few incorrect types.
They have getaddrinfo(3) as their backend, and accept port='http' etc. You can even omit (pass None to) either of host or port for start_server() to effectively select 'localhost' and an arbitrary ephemeral port, respectively.
Looked at https://github.com/requests/requests/blob/master/requests/structures.py.
The "data" argument to the CaseInsensitiveDict constructor is passed as is to .update(),
so I accept the same argument types as MutableMapping.update.
LookupDict is strangely named and implemented but the point seems to be that you
setattr its keys, and then can access them with both attribute access and subscripting.
See its usage in d1fb1a29ab/requests/status_codes.py (L102).
