DOC: Change document code prun in a row
- [x] closes #28026 
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Thanks @EunSeop, can you fix the CI please, seems like your change is making something fail. ![image](https://user-images.githubusercontent.com/6908807/63394923-e9036700-c3fc-11e9-822d-9e6fe3a2032b.png)
Seems working correctly @datapythonista strange thing is that this error was not visible (and thus catched) on Azure ..