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.
* Make {C,WIN,PY}FUNCTYPE's restype argument optional (for void returns)
* Make WinError return WindowsError
* Don't have Array explicitly inherit from Sized
(since inheriting from classes with different metaclasses causes problems,
and it is a protocol anyways)
* Have Array.__iter__ properly return an Iterator instead of an Iterable
* Support additional argument types for c_void_p parameters
* Don't allow passing bytes where a writable c_void_p is expected
* Fix type of ctypes._CDataMeta.__[r]mul__
* Rename ctypes._cparam to _CArgObject to match the real type name
* Fix value type of ctypes.HRESULT
* Add stub for ctypes.wintypes
* Fix trailing whitespace in ctypes.wintypes
* Add a workaround to ctypes.Array to fix incorrect typing in some cases
* Expand multiple assignments so mypy recognizes them as type aliases
* Rename ctypes._Pointer to pointer so it can be used externally
This is in our style guide. This is the last piece of offending code; I just submitted ambv/flake8-pyi#10 to enforce the rule in the linter in the future.
This was introduced in a recent version (so it doesn't affect us right now but will if we upgrade the flake8 version used in tests). It gives errors like:
```
/home/travis/build/ambv/flake8-pyi/.tox/typeshed/tmp/typeshed/stdlib/3/re.pyi:21:9: E741 ambiguous variable name 'I'
/home/travis/build/ambv/flake8-pyi/.tox/typeshed/tmp/typeshed/stdlib/3/re.pyi:39:5: E741 ambiguous variable name 'I'
/home/travis/build/ambv/flake8-pyi/.tox/typeshed/tmp/typeshed/stdlib/3/re.pyi:58:5: E741 ambiguous variable name 'I'
/home/travis/build/ambv/flake8-pyi/.tox/typeshed/tmp/typeshed/third_party/2/OpenSSL/crypto.pyi:43:5: E741 ambiguous variable name 'O'
```
These aren't useful for typeshed, because regardless of whether it's good style, these libraries really do contain variables named `I` and `O`.
* ArgumentParser's add_argument returns the Action that was created.
* Make add_argument's dest parameter Optional. _ArgumentGroup's add_argument should also return the Action.
Jelle Zijlstra