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 also propagate fillna using apply:

df2['newcolumn'] = df2[['AccountID_x','AccountId']].apply(lambda x: x.fillna(method='ffill')[-1], axis=1)

Or equivalently (in your case):

df2['newcolumn'] = df2[['AccountID_x','AccountId']].apply(lambda x: x.fillna(method='bfill')[0], axis=1)