DOC: fix pr09,pr08 errors in frame.py
fixing methods defined in this file
this is part of a larger clean up of
the dataframe class

this fixes a subset of #28702


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

Thanks @josibake 