pandas filling nans by mean of before and after non-nan values












6















I would like to fill df's nan with an average of adjacent elements.



Consider a dataframe:



df = pd.DataFrame({'val': [1,np.nan, 4, 5, np.nan, 10, 1,2,5, np.nan, np.nan, 9]})
val
0 1.0
1 NaN
2 4.0
3 5.0
4 NaN
5 10.0
6 1.0
7 2.0
8 5.0
9 NaN
10 NaN
11 9.0


My desired output is:



    val
0 1.0
1 2.5
2 4.0
3 5.0
4 7.5
5 10.0
6 1.0
7 2.0
8 5.0
9 7.0 <<< deadend
10 7.0 <<< deadend
11 9.0


I've looked into other solutions such as Fill cell containing NaN with average of value before and after, but this won't work in case of two or more consecutive np.nans.



Any help is greatly appreciated!










share|improve this question



























    6















    I would like to fill df's nan with an average of adjacent elements.



    Consider a dataframe:



    df = pd.DataFrame({'val': [1,np.nan, 4, 5, np.nan, 10, 1,2,5, np.nan, np.nan, 9]})
    val
    0 1.0
    1 NaN
    2 4.0
    3 5.0
    4 NaN
    5 10.0
    6 1.0
    7 2.0
    8 5.0
    9 NaN
    10 NaN
    11 9.0


    My desired output is:



        val
    0 1.0
    1 2.5
    2 4.0
    3 5.0
    4 7.5
    5 10.0
    6 1.0
    7 2.0
    8 5.0
    9 7.0 <<< deadend
    10 7.0 <<< deadend
    11 9.0


    I've looked into other solutions such as Fill cell containing NaN with average of value before and after, but this won't work in case of two or more consecutive np.nans.



    Any help is greatly appreciated!










    share|improve this question

























      6












      6








      6








      I would like to fill df's nan with an average of adjacent elements.



      Consider a dataframe:



      df = pd.DataFrame({'val': [1,np.nan, 4, 5, np.nan, 10, 1,2,5, np.nan, np.nan, 9]})
      val
      0 1.0
      1 NaN
      2 4.0
      3 5.0
      4 NaN
      5 10.0
      6 1.0
      7 2.0
      8 5.0
      9 NaN
      10 NaN
      11 9.0


      My desired output is:



          val
      0 1.0
      1 2.5
      2 4.0
      3 5.0
      4 7.5
      5 10.0
      6 1.0
      7 2.0
      8 5.0
      9 7.0 <<< deadend
      10 7.0 <<< deadend
      11 9.0


      I've looked into other solutions such as Fill cell containing NaN with average of value before and after, but this won't work in case of two or more consecutive np.nans.



      Any help is greatly appreciated!










      share|improve this question














      I would like to fill df's nan with an average of adjacent elements.



      Consider a dataframe:



      df = pd.DataFrame({'val': [1,np.nan, 4, 5, np.nan, 10, 1,2,5, np.nan, np.nan, 9]})
      val
      0 1.0
      1 NaN
      2 4.0
      3 5.0
      4 NaN
      5 10.0
      6 1.0
      7 2.0
      8 5.0
      9 NaN
      10 NaN
      11 9.0


      My desired output is:



          val
      0 1.0
      1 2.5
      2 4.0
      3 5.0
      4 7.5
      5 10.0
      6 1.0
      7 2.0
      8 5.0
      9 7.0 <<< deadend
      10 7.0 <<< deadend
      11 9.0


      I've looked into other solutions such as Fill cell containing NaN with average of value before and after, but this won't work in case of two or more consecutive np.nans.



      Any help is greatly appreciated!







      python pandas






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked 15 mins ago









      ChrisChris

      1,181213




      1,181213
























          1 Answer
          1






          active

          oldest

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          9














          Use ffill and bfill and divide by 2:



          df = (df.ffill()+df.bfill())/2

          print(df)
          val
          0 1.0
          1 2.5
          2 4.0
          3 5.0
          4 7.5
          5 10.0
          6 1.0
          7 2.0
          8 5.0
          9 7.0
          10 7.0
          11 9.0




          share



















          • 3





            That is just brilliant. Thanks a ton :)

            – Chris
            8 mins ago











          • @Chris Glad to help.

            – Sandeep Kadapa
            2 mins ago











          Your Answer






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          1 Answer
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          oldest

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          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          9














          Use ffill and bfill and divide by 2:



          df = (df.ffill()+df.bfill())/2

          print(df)
          val
          0 1.0
          1 2.5
          2 4.0
          3 5.0
          4 7.5
          5 10.0
          6 1.0
          7 2.0
          8 5.0
          9 7.0
          10 7.0
          11 9.0




          share



















          • 3





            That is just brilliant. Thanks a ton :)

            – Chris
            8 mins ago











          • @Chris Glad to help.

            – Sandeep Kadapa
            2 mins ago
















          9














          Use ffill and bfill and divide by 2:



          df = (df.ffill()+df.bfill())/2

          print(df)
          val
          0 1.0
          1 2.5
          2 4.0
          3 5.0
          4 7.5
          5 10.0
          6 1.0
          7 2.0
          8 5.0
          9 7.0
          10 7.0
          11 9.0




          share



















          • 3





            That is just brilliant. Thanks a ton :)

            – Chris
            8 mins ago











          • @Chris Glad to help.

            – Sandeep Kadapa
            2 mins ago














          9












          9








          9







          Use ffill and bfill and divide by 2:



          df = (df.ffill()+df.bfill())/2

          print(df)
          val
          0 1.0
          1 2.5
          2 4.0
          3 5.0
          4 7.5
          5 10.0
          6 1.0
          7 2.0
          8 5.0
          9 7.0
          10 7.0
          11 9.0




          share













          Use ffill and bfill and divide by 2:



          df = (df.ffill()+df.bfill())/2

          print(df)
          val
          0 1.0
          1 2.5
          2 4.0
          3 5.0
          4 7.5
          5 10.0
          6 1.0
          7 2.0
          8 5.0
          9 7.0
          10 7.0
          11 9.0





          share











          share


          share










          answered 9 mins ago









          Sandeep KadapaSandeep Kadapa

          6,813629




          6,813629








          • 3





            That is just brilliant. Thanks a ton :)

            – Chris
            8 mins ago











          • @Chris Glad to help.

            – Sandeep Kadapa
            2 mins ago














          • 3





            That is just brilliant. Thanks a ton :)

            – Chris
            8 mins ago











          • @Chris Glad to help.

            – Sandeep Kadapa
            2 mins ago








          3




          3





          That is just brilliant. Thanks a ton :)

          – Chris
          8 mins ago





          That is just brilliant. Thanks a ton :)

          – Chris
          8 mins ago













          @Chris Glad to help.

          – Sandeep Kadapa
          2 mins ago





          @Chris Glad to help.

          – Sandeep Kadapa
          2 mins ago


















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