http://pandas.pydata.org/pandas-docs/stable/tutorials.html
http://pandas.pydata.org/pandas-docs/stable/10min.html
2020
CoreySchafer - Pandas Tutorials 11pcs
    https://www.youtube.com/playlist?list=PL-osiE80TeTsWmV9i9c58mdDCSskIFdDS
2016
https://github.com/TomAugspurger/effective-pandas
    https://tomaugspurger.github.io/modern-1-intro.html
    https://tomaugspurger.github.io/method-chaining.html
    https://tomaugspurger.github.io/modern-3-indexes.html
    https://tomaugspurger.github.io/modern-4-performance
    https://tomaugspurger.github.io/modern-5-tidy
    https://tomaugspurger.github.io/modern-6-visualization
    https://tomaugspurger.github.io/modern-7-timeseries