Recently I discovered dropwhile and takewhile functions from itertools. It’s quite common problem within a given project to extract lines from a file starting with lines A, B and C.

Recently I stumbled upon a problem that pandas.read_csv() changed its date parsing behaviour in version 2.0.0. Long story short there was a need to have an environment specific csv reading method calls.

If you try to check for np.nan or None using pandas isna() to get a bool, that is either True or False.