Difference of two columns if condition is met












0















To get the difference between two columns of a pandas dataframe when specifying a condition I'm currently using the following code. For example, to get difference between column A and B for the rows where A > B:



import pandas as pd
df = pd.DataFrame({'A' : [4,5,6,7], 'B' : [1,2,10,11]}); df
A B
0 4 1
1 5 2
2 6 10
3 7 11

df2 = df.loc[df.A > df.B]
df2.A - df2.B
0 3
1 3


Is there a way to "pipe" this instead of creating the temporary dataframe df2 above?










share|improve this question



























    0















    To get the difference between two columns of a pandas dataframe when specifying a condition I'm currently using the following code. For example, to get difference between column A and B for the rows where A > B:



    import pandas as pd
    df = pd.DataFrame({'A' : [4,5,6,7], 'B' : [1,2,10,11]}); df
    A B
    0 4 1
    1 5 2
    2 6 10
    3 7 11

    df2 = df.loc[df.A > df.B]
    df2.A - df2.B
    0 3
    1 3


    Is there a way to "pipe" this instead of creating the temporary dataframe df2 above?










    share|improve this question

























      0












      0








      0








      To get the difference between two columns of a pandas dataframe when specifying a condition I'm currently using the following code. For example, to get difference between column A and B for the rows where A > B:



      import pandas as pd
      df = pd.DataFrame({'A' : [4,5,6,7], 'B' : [1,2,10,11]}); df
      A B
      0 4 1
      1 5 2
      2 6 10
      3 7 11

      df2 = df.loc[df.A > df.B]
      df2.A - df2.B
      0 3
      1 3


      Is there a way to "pipe" this instead of creating the temporary dataframe df2 above?










      share|improve this question














      To get the difference between two columns of a pandas dataframe when specifying a condition I'm currently using the following code. For example, to get difference between column A and B for the rows where A > B:



      import pandas as pd
      df = pd.DataFrame({'A' : [4,5,6,7], 'B' : [1,2,10,11]}); df
      A B
      0 4 1
      1 5 2
      2 6 10
      3 7 11

      df2 = df.loc[df.A > df.B]
      df2.A - df2.B
      0 3
      1 3


      Is there a way to "pipe" this instead of creating the temporary dataframe df2 above?







      pandas dataframe






      share|improve this question













      share|improve this question











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      share|improve this question










      asked Nov 16 '18 at 10:43









      PedroAPedroA

      635823




      635823
























          2 Answers
          2






          active

          oldest

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          1














          One method using eval and has high performance while working with huge data:



          df.loc[df.A > df.B].eval('A - B')

          0 3
          1 3
          dtype: int64





          share|improve this answer

































            1














            Simply join the two commands and select the columns you want to subtract:



            In [2337]: df.loc[df.A > df.B]['A'] - df.loc[df.A > df.B]['B']
            Out[2337]:
            0 3
            1 3
            dtype: int64





            share|improve this answer
























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              2 Answers
              2






              active

              oldest

              votes








              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              1














              One method using eval and has high performance while working with huge data:



              df.loc[df.A > df.B].eval('A - B')

              0 3
              1 3
              dtype: int64





              share|improve this answer






























                1














                One method using eval and has high performance while working with huge data:



                df.loc[df.A > df.B].eval('A - B')

                0 3
                1 3
                dtype: int64





                share|improve this answer




























                  1












                  1








                  1







                  One method using eval and has high performance while working with huge data:



                  df.loc[df.A > df.B].eval('A - B')

                  0 3
                  1 3
                  dtype: int64





                  share|improve this answer















                  One method using eval and has high performance while working with huge data:



                  df.loc[df.A > df.B].eval('A - B')

                  0 3
                  1 3
                  dtype: int64






                  share|improve this answer














                  share|improve this answer



                  share|improve this answer








                  edited Nov 16 '18 at 11:15

























                  answered Nov 16 '18 at 10:46









                  Sandeep KadapaSandeep Kadapa

                  7,398831




                  7,398831

























                      1














                      Simply join the two commands and select the columns you want to subtract:



                      In [2337]: df.loc[df.A > df.B]['A'] - df.loc[df.A > df.B]['B']
                      Out[2337]:
                      0 3
                      1 3
                      dtype: int64





                      share|improve this answer




























                        1














                        Simply join the two commands and select the columns you want to subtract:



                        In [2337]: df.loc[df.A > df.B]['A'] - df.loc[df.A > df.B]['B']
                        Out[2337]:
                        0 3
                        1 3
                        dtype: int64





                        share|improve this answer


























                          1












                          1








                          1







                          Simply join the two commands and select the columns you want to subtract:



                          In [2337]: df.loc[df.A > df.B]['A'] - df.loc[df.A > df.B]['B']
                          Out[2337]:
                          0 3
                          1 3
                          dtype: int64





                          share|improve this answer













                          Simply join the two commands and select the columns you want to subtract:



                          In [2337]: df.loc[df.A > df.B]['A'] - df.loc[df.A > df.B]['B']
                          Out[2337]:
                          0 3
                          1 3
                          dtype: int64






                          share|improve this answer












                          share|improve this answer



                          share|improve this answer










                          answered Nov 16 '18 at 10:47









                          Mayank PorwalMayank Porwal

                          5,0182725




                          5,0182725






























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