fix frame, generic, series.py
- [x] xref #38138
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry
        Identify unnecessary dict call - rewrite as a literal

thanks @liudj2008  Thank you @ivanovmg and @jreback . Will look more issues with pandas!