Home create dataframe from df1 and df2 and take empty value from df2 for column value if not exist in df1 column value

Questions

create dataframe from df1 and df2 and take empty value from df2 for column value if not exist in df1 column value

February 16, 2023

df1 = pd.DataFrame({'call_sign': ['ASD','BSD','CDSF','GFDFD','FHHH'],'frn':['123','124','','656','']})

df2 = pd.DataFrame({'call_sign': ['ASD','CDSF','BSD','GFDFD','FHHH'],'frn':['1234','','124','','765']})

need to get a new df like

df2 = pd.DataFrame({'call_sign': ['ASD','BSD','CDSF','GFDFD','FHHH'],'frn':['123','','124','656','765']})

ie: need to take frn from df2 if it’s missing in df1 and create a new df

>Solution :

Replace empty strings to missing values and use DataFrame.set_index with DataFrame.fillna, because need ordering like df2.call_sign add DataFrame.reindex:

df = (df1.set_index('call_sign').replace('', np.nan)
          .fillna(df2.set_index('call_sign').replace('', np.nan))
         .reindex(df2['call_sign']).reset_index())
print(df)
  call_sign  frn
0       ASD  123
1      CDSF  NaN
2       BSD  124
3     GFDFD  656
4      FHHH  765