DOC: Fixing EX01 - Added examples
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).

Towards https://github.com/pandas-dev/pandas/issues/37875

I don't know why the May 18 commits (of a branch that is already deleted) are shown here, but the  changes are the ones I wanted to include on this PR
Thanks @DeaMariaLeon  Thank you @mroeschke 