Min max sparse
- [x] closes #40921
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [x] whatsnew entry

Hello @taytzehao! 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 2021-04-27 08:13:18 UTC pre-commit is failing, pls run the hooks: https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#pre-commit cc @jbrockmendel  thanks @taytzehao  @jreback this wasnt ready, in particular https://github.com/pandas-dev/pandas/pull/41159#discussion_r621602882 looks sketchy ok feel free to revert @taytzehao would you prefer to revert or to address this in a follow-up?