PR09 batch 4
chunk of #28602 
Hello @HughKelley! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:



















There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2019-11-08 14:41:27 UTC I'm unsure how to format line 133 in pandas/io/excel/_base.py. flake8 is picking up the space argument required to correctly format the list being inserted as an inappropriate indent.  > I'm unsure how to format line 133 in pandas/io/excel/_base.py. flake8 is picking up the space argument required to correctly format the list being inserted as an inappropriate indent.

What was the issue you faced previously? > What was the issue you faced previously?

Was adding indentation to the docstring while adding a period to a parameter description here: https://github.com/pandas-dev/pandas/pull/29466/commits/020e253c7f6eff26fa02877628e9ee4c5ec65e1a

it required changing the indentation argument to `textwrap.fill()` (inserted a list of NaN values into the string) from 4 spaces to 8 to match the rest of the string.  Hmm can you post the built HTML doc? Looks OK on stable docs wouldn't expect to have to change the indent

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_excel.html I was adding a period and thought the indentation should match throughout the string like below but if it's ok I'll undo that change.

``` python
example = (
    """
summary

Parameters
----------
parameter_1 :  str
    Description.
"""
)
``` 
changed to 
```
example = (
    """
    summary

    Parameters
    ----------
    parameter_1 :  str
        Description.
    """
   )
 @WillAyd `./scripts/validate_docstrings.py` wasn't picking up the period at the end of the `use_cols` parameter description. 

Adding an indent to the doc_string as I did in 020e253 resolved that but required adding 4 more spaces to the separator argument in `fill()` which created the `E131 hanging indent` error  Are we talking about `usecols` or `na_values`? I think I'm confused as to the source.

In any case I think OK to tweak slightly to get it to pass validation (i.e. adding text after bullets, or something to the effect)

@datapythonista  > Are we talking about `usecols` or `na_values`? I think I'm confused as to the source.

The original error i was trying to fix was the a missing period for `use_cols`. I fixed that by indenting the string. that created a new error in `na_values` where in order to format the list correctly I had to add spaces to the separator argument which flake8 was then picking up as a hanging indent.  > If you want to remove the remaining `Behaves as:` and `Behavior:` that would be great, but lgtm

ah thanks @WillAyd and @datapythonista checks are green. Thanks very much for the help on this one! Thanks a lot for helping fix the documentation @HughKelley 