DOC: Fix quotes position in pandas.core
- [X] closes #24071
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
Hello @giantpanpan! Thanks for submitting the PR.

 - There are no PEP8 issues in the file [`pandas/core/base.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/base.py) !

 - In the file [`pandas/core/frame.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/frame.py), following                are the PEP8 issues :
> [Line 7063:80](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/frame.py#L7063): [E501](https://duckduckgo.com/?q=pep8%20E501) line too long (80 > 79 characters)


 - There are no PEP8 issues in the file [`pandas/core/generic.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/generic.py) !

 - There are no PEP8 issues in the file [`pandas/core/groupby/generic.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/groupby/generic.py) !

 - In the file [`pandas/core/groupby/groupby.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/groupby/groupby.py), following                are the PEP8 issues :
> [Line 1316:12](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/groupby/groupby.py#L1316): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
> [Line 1327:26](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/groupby/groupby.py#L1327): [E225](https://duckduckgo.com/?q=pep8%20E225) missing whitespace around operator
> [Line 1330:25](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/groupby/groupby.py#L1330): [E225](https://duckduckgo.com/?q=pep8%20E225) missing whitespace around operator


 - There are no PEP8 issues in the file [`pandas/core/series.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/series.py) !

 - There are no PEP8 issues in the file [`pandas/core/window.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/core/window.py) !

 - There are no PEP8 issues in the file [`pandas/plotting/_core.py`](https://github.com/giantpanpan/pandas/blob/e4d49e3d232915a23c3b01367452b3f00741f939/pandas/plotting/_core.py) !

 pls push to the same PR rather than opening new ones Thanks for the PR @giantpanpan 

Some general comments:
- When you open a pull request, in the title you can copy the description of the issue (or write a short summary of what you are fixing.
- In the description, keep the template we provide. It's a checklist of things that you should check while opening the PR. In this case, as this is only documentation minor fixing, you can ignore the ones about tests and about the whatsnew section. But you should check the one for the issue you're closing and write the issue number on it, and also execute the git command specified, and check it to know that you did it. If you see the comment from `pep8speaks`, you would find out about those errors before opening the pull request.

Then, regarding the pull request, I think you misunderstood what is the right and what is the wrong format. This is the correct:
```
def foo():
    """
    Summary of the docstring.

    Returns
    -------
    str
        Explaining what is being returned.
    """
```

And you shouldn't create docstrings for the methods that don't have them in this same PR (besides that the ones created have some template that I guess your editor added, that is not correct).

I think it probably makes sense to start over again. My recommendation is that:
- You clone the repository again
- You create a branch to work on your changes (`git checkout -b fixing_quotes`)
- You fix only the issues reported by the command in the issue description
- You open a new PR

Please let me know if  you need any help. You can ask in the issue comments as you did before.
