Fix Type Annotations in pandas.core.generic

[WillAyd]

Part of #25882

Current errors are as follows:

pandas/core/generic.py:116: error: Need type annotation for '_accessors'
pandas/core/generic.py:119: error: Need type annotation for '_metadata'

Both of these are containers which should contain strings, so just need proper annotation and this module can be removed from mypy.ini

[WillAyd]

Also makes sense to clean up a similar error in the frame module:

pandas/core/frame.py:368: error: Need type annotation for '_accessors'

[vaibhavhrt]

I think we need to add a comment like this: # type: List[str] or

from typing import Container
_metadata: Container[str] = []

right? I can do that. But I have never contributed to open source before so if you can help me a bit if I get stuck somewhere it will be nice.

[vaibhavhrt]

Hi, I tried _metadata: Container[str] = [] but now pep8 gives me error that:

pandas/core/generic.py:120:14: E701 multiple statements on one line (colon)

Should I use the the comment syntax # type: Container[str] or can we ignore this error?

[WillAyd]

Yea for local variables need comment syntax as we still support Py35 and that didn’t come until Py36. Should use List here

…

Sent from my iPhone

On Mar 28, 2019, at 4:37 AM, Vaibhav Vishal ***@***.***> wrote: Hi, I tried _metadata: Container[str] = [] but now pep8 gives me error that: pandas/core/generic.py:120:14: E701 multiple statements on one line (colon) Should I use the the comment syntax # type: Container[str] or can we ignore this error? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[vaibhavhrt]

Thanks, I will fix this and open a pull request. There are some other open issues related to Type Annotation, should I fix them too in the same PR, or you want different PR for each one?

Also looking at the code _metadata looks like a list to me, should I use List[str] or Container[str]

[WillAyd]

Use List and one PR per issue for now

…

Sent from my iPhone

On Mar 28, 2019, at 5:39 AM, Vaibhav Vishal ***@***.***> wrote: Thanks, I will fix this and open a pull request. There are some other open issues related to Type Annotation, should I fix them too in the same PR, or you want different PR for each one? Also looking at the code _metadata looks like a list to me, should I use List[str] or Container[str] — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[vaibhavhrt]

ok. You said list in your last comment, sorry I missed that, my bad. I was looking at your very first comment which said both are containers.