Fill Empty Values from another Column
Date: 25 March 2018
Category: Python
Tags: Pandas, Neat Tricks
Credit: Stack Overflow
If you want to create a column which uses a value from one column when it is not blank, and a value from another when it is, the following trick can be used:
df['Col3'] = df['Col1'] # Where Col1 is known to contain some blanks
df['Col3'].fillna(df['Col2'])