DOC: Corrects 'reindex_axis' docstring
The docstring included a 'tolerance' parameter which is missing from the source. This has been removed.

The docstring did not describe the 'fill_value' parameter. This has been added, mostly reusing the wording in the summary part of the existing docstring.

- [x] closes #23960
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Hello @eahogue! Thanks for updating the PR.

 - There are no PEP8 issues in the file [`pandas/core/generic.py`](https://github.com/eahogue/pandas/blob/822dca1030cbb2ee922be676d9a37fcbf1466d07/pandas/core/generic.py) !



##### Comment last updated on December 08, 2018 at 23:57 Hours UTC # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=h1) Report
> Merging [#24105](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/4b5f4d1a59a7fce09c47eb0c03ba99a6cea472c6?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24105/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24105      +/-   ##
==========================================
- Coverage   92.21%    92.2%   -0.01%     
==========================================
  Files         161      161              
  Lines       51684    51684              
==========================================
- Hits        47658    47657       -1     
- Misses       4026     4027       +1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.61% <100%> (ø)` | :arrow_up: |
| #single | `43% <100%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/24105/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `96.65% <100%> (ø)` | :arrow_up: |
| [pandas/io/json/json.py](https://codecov.io/gh/pandas-dev/pandas/pull/24105/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2pzb24vanNvbi5weQ==) | `92.61% <0%> (-0.48%)` | :arrow_down: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24105/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `87.48% <0%> (+0.09%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=footer). Last update [4b5f4d1...ffbad45](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=h1) Report
> Merging [#24105](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/67faf6c32c52b55ed61b01d72841a703dcc8d210?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24105/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24105      +/-   ##
==========================================
- Coverage    92.2%    92.2%   -0.01%     
==========================================
  Files         162      162              
  Lines       51700    51700              
==========================================
- Hits        47671    47670       -1     
- Misses       4029     4030       +1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.6% <ø> (-0.01%)` | :arrow_down: |
| #single | `43.02% <ø> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/24105/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `96.65% <ø> (ø)` | :arrow_up: |
| [pandas/core/internals/blocks.py](https://codecov.io/gh/pandas-dev/pandas/pull/24105/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzL2Jsb2Nrcy5weQ==) | `93.65% <0%> (-0.07%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=footer). Last update [67faf6c...201ef53](https://codecov.io/gh/pandas-dev/pandas/pull/24105?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Thanks for the fix @eahogue 

Do you mind running `./scripts/validate_docstrings.py pandas.DataFrame.reindex_axis` to see if there is any other error.

I think a short summary is missing (a one liner summary), the `Returns` doesn't have a description, and the example is missing the output.

If you don't mind fixing those, and anything else reported by the script, or that you see, that would be great. So we leave this docstring perfect. Thanks, @datapythonista. I have made additional changes and hope I have committed etc correctly. The validation script no longer returns errors. PTAL. can you merge master @eahogue can you fix the conflicts

Also, the deprecation directive should be places between the short and the extended summary, seems like we're doing it wrong in most places: https://numpydoc.readthedocs.io/en/latest/format.html#sections

I create #24143to fix the remaining errors. Sorry for the basic question, but the tests have passed but I am not sure what else needs to be done. Have the changes gone through yet? I think all comments were addressed, so nothing needed to be done any more (except someone merging it).

@eahogue Thanks a lot!