CLN: Centralised _check_percentile
- Fixes  #27559
- Moved the _check_percentile method on NDFrame to algorithms as
check_percentile.
- Changed the references to _check_percentile in pandas/core/series.py
and pandas/core/frame.py

- [x] closes #27559
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Can you also update the groupby reference from the OP? > See above comment

Sorry I couldn't figure out what it was referring to. I didnt find any references to _check_percentile in groupby. Can you help me figure it out?  Oh sorry misread that on my end - not there yet for groupby so I think OK for now ok will have to backport this as #27473 depends Hello @hedonhermdev! 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 2019-10-03 15:22:43 UTC @hedonhermdev seems like there's still a linting issue, and maybe some CI failures. @hedonhermdev can you update? Pushing to 1.0 @hedonhermdev can you rebase Nice idea but I think this has gone stale. @hedonhermdev please ping if you'd like to pick this back up Hey sorry for the disappearance, if possible I would like to work on it again. Can you reopen the pull request?  Sure - thanks for the contribution  @WillAyd does this look good for merging? I fixed the typing error.  Yes I did, couldn’t find any references in groupby. That will probably be added after #27559 gets resolved.  Looks like a linting failure: https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=17752

Try running `black pandas`. Instructions are in the contributing guide. @hedonhermdev linting issue: https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=17804

In the future, I'd recommend using pre-commit as described in https://dev.pandas.io/docs/development/contributing.html#python-pep8-black @jbrockmendel  should I modify excel.py too? As I'm getting a linting issue because of it.  It looks like it just wants you to revert the whitespace change in the excel.py file thanks @hedonhermdev 