How to pick specific columns Pandas dataframe when checking against NaN

Question

I have a pandas dataframe in Python that looks something like

       AccountID_x    AccountId  AmountCD_x  AmountDOC_x  AmountDoc_x  
1              NaN  4001001         


        

Answer 1

You can use combine_first to combine the two

df['new_col'] = df['AccountId'].combine_first(df['AccountID_x'])

df['new_col']

1    4001001copa
2    4001001copa
3    4001001copa
4    4001001copa