STY: "{foo!r}" -> "{repr(foo)}" #batch-3
- [x] ref #29886
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Hello @MomIsBestFriend! 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 2019-12-09 11:15:26 UTC cc @simonjayhawkins @WillAyd  lgtm ping on green ping @jreback  Thanks @MomIsBestFriend 