reshaping data frame and applying calculation for each row












2















I have a data frame as follows:



df=pd.DataFrame({ 'family' : ["A","A","B","B"],
'V1' : [5,5,40,10,],
'V2' :[50,10,180,20],
'gr_0' :["all","all","all","all"],
'gr_1' :["m1","m1","m2","m3"],
'gr_2' :["m12","m12","m12","m9"],
'gr_3' :["NO","m14","m15","NO"]
})


and I would like to transform it in the following way:



df_new=pd.DataFrame({ 'family' : ["A","A","A","A","B","B","B","B","B","B"],
'gr' : ["all","m1","m12","m14","all","m2","m3","m12","m9","m15"],
"calc(sumV2/sumV1)":[6,6,6,2,4,4.5,2,4.5,2,4.5]
})




  family   gr  calc(sumV2/sumV1)
0 A all 6.0
1 A m1 6.0
2 A m12 6.0
3 A m14 2.0
4 B all 4.0
5 B m2 4.5
6 B m3 2.0
7 B m12 4.5
8 B m9 2.0
9 B m15 4.5


In order to reach to df_new:




  1. I want the rows to be aligned by "family" X each unique value of "gr_" columns.

  2. For every line to calculate the respective sum(V2)/sum(V1) as shown in the df_new.


I am quite new to python. Softcoding of this seems quite complex to me.
Preferably, I don't want "No" records to be listed in this df_new but it can stay in the output as well.










share|improve this question





























    2















    I have a data frame as follows:



    df=pd.DataFrame({ 'family' : ["A","A","B","B"],
    'V1' : [5,5,40,10,],
    'V2' :[50,10,180,20],
    'gr_0' :["all","all","all","all"],
    'gr_1' :["m1","m1","m2","m3"],
    'gr_2' :["m12","m12","m12","m9"],
    'gr_3' :["NO","m14","m15","NO"]
    })


    and I would like to transform it in the following way:



    df_new=pd.DataFrame({ 'family' : ["A","A","A","A","B","B","B","B","B","B"],
    'gr' : ["all","m1","m12","m14","all","m2","m3","m12","m9","m15"],
    "calc(sumV2/sumV1)":[6,6,6,2,4,4.5,2,4.5,2,4.5]
    })




      family   gr  calc(sumV2/sumV1)
    0 A all 6.0
    1 A m1 6.0
    2 A m12 6.0
    3 A m14 2.0
    4 B all 4.0
    5 B m2 4.5
    6 B m3 2.0
    7 B m12 4.5
    8 B m9 2.0
    9 B m15 4.5


    In order to reach to df_new:




    1. I want the rows to be aligned by "family" X each unique value of "gr_" columns.

    2. For every line to calculate the respective sum(V2)/sum(V1) as shown in the df_new.


    I am quite new to python. Softcoding of this seems quite complex to me.
    Preferably, I don't want "No" records to be listed in this df_new but it can stay in the output as well.










    share|improve this question



























      2












      2








      2


      1






      I have a data frame as follows:



      df=pd.DataFrame({ 'family' : ["A","A","B","B"],
      'V1' : [5,5,40,10,],
      'V2' :[50,10,180,20],
      'gr_0' :["all","all","all","all"],
      'gr_1' :["m1","m1","m2","m3"],
      'gr_2' :["m12","m12","m12","m9"],
      'gr_3' :["NO","m14","m15","NO"]
      })


      and I would like to transform it in the following way:



      df_new=pd.DataFrame({ 'family' : ["A","A","A","A","B","B","B","B","B","B"],
      'gr' : ["all","m1","m12","m14","all","m2","m3","m12","m9","m15"],
      "calc(sumV2/sumV1)":[6,6,6,2,4,4.5,2,4.5,2,4.5]
      })




        family   gr  calc(sumV2/sumV1)
      0 A all 6.0
      1 A m1 6.0
      2 A m12 6.0
      3 A m14 2.0
      4 B all 4.0
      5 B m2 4.5
      6 B m3 2.0
      7 B m12 4.5
      8 B m9 2.0
      9 B m15 4.5


      In order to reach to df_new:




      1. I want the rows to be aligned by "family" X each unique value of "gr_" columns.

      2. For every line to calculate the respective sum(V2)/sum(V1) as shown in the df_new.


      I am quite new to python. Softcoding of this seems quite complex to me.
      Preferably, I don't want "No" records to be listed in this df_new but it can stay in the output as well.










      share|improve this question
















      I have a data frame as follows:



      df=pd.DataFrame({ 'family' : ["A","A","B","B"],
      'V1' : [5,5,40,10,],
      'V2' :[50,10,180,20],
      'gr_0' :["all","all","all","all"],
      'gr_1' :["m1","m1","m2","m3"],
      'gr_2' :["m12","m12","m12","m9"],
      'gr_3' :["NO","m14","m15","NO"]
      })


      and I would like to transform it in the following way:



      df_new=pd.DataFrame({ 'family' : ["A","A","A","A","B","B","B","B","B","B"],
      'gr' : ["all","m1","m12","m14","all","m2","m3","m12","m9","m15"],
      "calc(sumV2/sumV1)":[6,6,6,2,4,4.5,2,4.5,2,4.5]
      })




        family   gr  calc(sumV2/sumV1)
      0 A all 6.0
      1 A m1 6.0
      2 A m12 6.0
      3 A m14 2.0
      4 B all 4.0
      5 B m2 4.5
      6 B m3 2.0
      7 B m12 4.5
      8 B m9 2.0
      9 B m15 4.5


      In order to reach to df_new:




      1. I want the rows to be aligned by "family" X each unique value of "gr_" columns.

      2. For every line to calculate the respective sum(V2)/sum(V1) as shown in the df_new.


      I am quite new to python. Softcoding of this seems quite complex to me.
      Preferably, I don't want "No" records to be listed in this df_new but it can stay in the output as well.







      python python-3.x pandas pivot-table pandas-groupby






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 15 '18 at 17:55









      user3483203

      31.4k82656




      31.4k82656










      asked Nov 15 '18 at 16:22









      glsvmkyglsvmky

      111




      111
























          2 Answers
          2






          active

          oldest

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          2














          You can do so with this:



          df_new = df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)')
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          print(df_new)

          family value calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0





          share|improve this answer





















          • 1





            Thanks for that @Ben.T :)

            – yatu
            Nov 15 '18 at 16:47





















          1















          melt + groupby:



          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()

          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')




            family   gr  calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0




          A similar approach to this answer, but with the benefit of being fully vectorized, and avoiding apply





          Performance:



          a = np.random.randint(1, 1000, (1_000_000, 7))
          df = pd.DataFrame(a, columns=['family', 'V1', 'V2', 'gr_0', 'gr_1', 'gr_2', 'gr_3'])
          df[['gr_0', 'gr_1', 'gr_2', 'gr_3']] = df[['gr_0', 'gr_1', 'gr_2', 'gr_3']].astype(str)

          %%timeit
          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()
          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')

          2.71 s ± 32.9 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

          %%timeit
          df_new = (df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)'))
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          5min 24s ± 3.35 s per loop (mean ± std. dev. of 7 runs, 1 loop each)





          share|improve this answer


























          • @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

            – user3483203
            Nov 15 '18 at 17:54











          • Fair point @user3483203

            – yatu
            Nov 15 '18 at 19:01











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          2 Answers
          2






          active

          oldest

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          2 Answers
          2






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          2














          You can do so with this:



          df_new = df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)')
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          print(df_new)

          family value calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0





          share|improve this answer





















          • 1





            Thanks for that @Ben.T :)

            – yatu
            Nov 15 '18 at 16:47


















          2














          You can do so with this:



          df_new = df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)')
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          print(df_new)

          family value calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0





          share|improve this answer





















          • 1





            Thanks for that @Ben.T :)

            – yatu
            Nov 15 '18 at 16:47
















          2












          2








          2







          You can do so with this:



          df_new = df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)')
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          print(df_new)

          family value calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0





          share|improve this answer















          You can do so with this:



          df_new = df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)')
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          print(df_new)

          family value calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0






          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 15 '18 at 16:47

























          answered Nov 15 '18 at 16:33









          yatuyatu

          13.2k31341




          13.2k31341








          • 1





            Thanks for that @Ben.T :)

            – yatu
            Nov 15 '18 at 16:47
















          • 1





            Thanks for that @Ben.T :)

            – yatu
            Nov 15 '18 at 16:47










          1




          1





          Thanks for that @Ben.T :)

          – yatu
          Nov 15 '18 at 16:47







          Thanks for that @Ben.T :)

          – yatu
          Nov 15 '18 at 16:47















          1















          melt + groupby:



          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()

          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')




            family   gr  calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0




          A similar approach to this answer, but with the benefit of being fully vectorized, and avoiding apply





          Performance:



          a = np.random.randint(1, 1000, (1_000_000, 7))
          df = pd.DataFrame(a, columns=['family', 'V1', 'V2', 'gr_0', 'gr_1', 'gr_2', 'gr_3'])
          df[['gr_0', 'gr_1', 'gr_2', 'gr_3']] = df[['gr_0', 'gr_1', 'gr_2', 'gr_3']].astype(str)

          %%timeit
          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()
          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')

          2.71 s ± 32.9 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

          %%timeit
          df_new = (df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)'))
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          5min 24s ± 3.35 s per loop (mean ± std. dev. of 7 runs, 1 loop each)





          share|improve this answer


























          • @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

            – user3483203
            Nov 15 '18 at 17:54











          • Fair point @user3483203

            – yatu
            Nov 15 '18 at 19:01
















          1















          melt + groupby:



          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()

          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')




            family   gr  calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0




          A similar approach to this answer, but with the benefit of being fully vectorized, and avoiding apply





          Performance:



          a = np.random.randint(1, 1000, (1_000_000, 7))
          df = pd.DataFrame(a, columns=['family', 'V1', 'V2', 'gr_0', 'gr_1', 'gr_2', 'gr_3'])
          df[['gr_0', 'gr_1', 'gr_2', 'gr_3']] = df[['gr_0', 'gr_1', 'gr_2', 'gr_3']].astype(str)

          %%timeit
          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()
          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')

          2.71 s ± 32.9 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

          %%timeit
          df_new = (df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)'))
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          5min 24s ± 3.35 s per loop (mean ± std. dev. of 7 runs, 1 loop each)





          share|improve this answer


























          • @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

            – user3483203
            Nov 15 '18 at 17:54











          • Fair point @user3483203

            – yatu
            Nov 15 '18 at 19:01














          1












          1








          1








          melt + groupby:



          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()

          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')




            family   gr  calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0




          A similar approach to this answer, but with the benefit of being fully vectorized, and avoiding apply





          Performance:



          a = np.random.randint(1, 1000, (1_000_000, 7))
          df = pd.DataFrame(a, columns=['family', 'V1', 'V2', 'gr_0', 'gr_1', 'gr_2', 'gr_3'])
          df[['gr_0', 'gr_1', 'gr_2', 'gr_3']] = df[['gr_0', 'gr_1', 'gr_2', 'gr_3']].astype(str)

          %%timeit
          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()
          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')

          2.71 s ± 32.9 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

          %%timeit
          df_new = (df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)'))
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          5min 24s ± 3.35 s per loop (mean ± std. dev. of 7 runs, 1 loop each)





          share|improve this answer
















          melt + groupby:



          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()

          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')




            family   gr  calc(sumV2/sumV1)
          0 A all 6.0
          1 A m1 6.0
          2 A m12 6.0
          3 A m14 2.0
          4 B all 4.0
          5 B m12 4.5
          6 B m15 4.5
          7 B m2 4.5
          8 B m3 2.0
          9 B m9 2.0




          A similar approach to this answer, but with the benefit of being fully vectorized, and avoiding apply





          Performance:



          a = np.random.randint(1, 1000, (1_000_000, 7))
          df = pd.DataFrame(a, columns=['family', 'V1', 'V2', 'gr_0', 'gr_1', 'gr_2', 'gr_3'])
          df[['gr_0', 'gr_1', 'gr_2', 'gr_3']] = df[['gr_0', 'gr_1', 'gr_2', 'gr_3']].astype(str)

          %%timeit
          v = df.melt(id_vars=['family','V1','V2'], value_name='gr')
          w = v.loc[v.gr != 'NO']
          x = w.groupby(['family', 'gr']).sum()
          (x.V2 / x.V1).reset_index(name='calc(sumV2/sumV1)')

          2.71 s ± 32.9 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

          %%timeit
          df_new = (df.melt(id_vars=['family','V1','V2']).groupby(['family','value'])
          .apply(lambda x: x.V2.sum()/x.V1.sum())
          .reset_index(name='calc(sumV2/sumV1)'))
          df_new = df_new[df_new.value != 'NO'].reset_index(drop=True)

          5min 24s ± 3.35 s per loop (mean ± std. dev. of 7 runs, 1 loop each)






          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 15 '18 at 17:53

























          answered Nov 15 '18 at 16:47









          user3483203user3483203

          31.4k82656




          31.4k82656













          • @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

            – user3483203
            Nov 15 '18 at 17:54











          • Fair point @user3483203

            – yatu
            Nov 15 '18 at 19:01



















          • @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

            – user3483203
            Nov 15 '18 at 17:54











          • Fair point @user3483203

            – yatu
            Nov 15 '18 at 19:01

















          @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

          – user3483203
          Nov 15 '18 at 17:54





          @AlexandreNixon similar in approach, but I just added timings to show why apply should really be avoided. Vectorized operations make a big difference

          – user3483203
          Nov 15 '18 at 17:54













          Fair point @user3483203

          – yatu
          Nov 15 '18 at 19:01





          Fair point @user3483203

          – yatu
          Nov 15 '18 at 19:01


















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