No documentation in suggestions for value returned from `open`

[mjbvz]

Issue Type: Bug

Repro

1. with the python code:

with open('x') as f:
    f.

2. Trigger suggestions on f

Bug
See suggestions but no documentation for these suggestion:

Both the signature of the method and the documentation for it should be shown here

In this case, the documentation should probably come from https://docs.python.org/3/library/io.html#i-o-base-classes but I'm not familiar enough with python to say for sure

Extension version: 2020.4.68060-dev
VS Code version: Code - Insiders 1.44.0-insider (efd7548df65de8e775015b67863190e6bd4934fc, 2020-03-13T06:01:51.669Z)
OS version: Darwin x64 19.3.0

[mjbvz]

Still no documentation with Jedi disabled but it does start showing some signatures:

[MikhailArkhipov]

This is b/c type returned is specialized in code depending on options/arguments passed so I guess some info is getting lost in specialization code.

[MikhailArkhipov]

So there is no documentation neither in stub nor in a scraped data from builtins. Scrcaped:

class TextIOWrapper(_TextIOBase):
...
    def close(self):
        pass 
    def detach(self):
        pass
    def flush(self):
        pass
...

and obviously, there are no doc strings in typeshed stub either. The issue seems to be in the scraper script since on x which is f.close, getattr does retrieve proper __doc__

>>> getattr(x, '__doc__')
'close() -> None or (perhaps) an integer.  Close the file.\n\nSets data attribute .closed to True. 
A closed file cannot be used for\nfurther I/O operations.  close() may be called more than once
without\nerror.  Some kinds of file objects (for example, opened by popen())\nmay return an exit
status upon closing.'