Averaging value based off previous value Python












0















I have a dataframe that looks like:



value 1         value 2
1 10
4 1
5 8
6 10
10 12


I want to go down each entry of value 1, average the previous value, and then create a new column beside value 2 with the average.



The output needs to look like:



value 1         value 2        avg
1 10 nan
4 1 2.5
5 8 4.5
6 10 5.5
10 12 8.0
.
.


How would I go about doing this?










share|improve this question























  • It all depends on how the data is represented. Do you have a list? A list of lists? Try to explain it in the question and add an example of what you tried so far.

    – Marco Bonelli
    Nov 16 '18 at 0:27
















0















I have a dataframe that looks like:



value 1         value 2
1 10
4 1
5 8
6 10
10 12


I want to go down each entry of value 1, average the previous value, and then create a new column beside value 2 with the average.



The output needs to look like:



value 1         value 2        avg
1 10 nan
4 1 2.5
5 8 4.5
6 10 5.5
10 12 8.0
.
.


How would I go about doing this?










share|improve this question























  • It all depends on how the data is represented. Do you have a list? A list of lists? Try to explain it in the question and add an example of what you tried so far.

    – Marco Bonelli
    Nov 16 '18 at 0:27














0












0








0








I have a dataframe that looks like:



value 1         value 2
1 10
4 1
5 8
6 10
10 12


I want to go down each entry of value 1, average the previous value, and then create a new column beside value 2 with the average.



The output needs to look like:



value 1         value 2        avg
1 10 nan
4 1 2.5
5 8 4.5
6 10 5.5
10 12 8.0
.
.


How would I go about doing this?










share|improve this question














I have a dataframe that looks like:



value 1         value 2
1 10
4 1
5 8
6 10
10 12


I want to go down each entry of value 1, average the previous value, and then create a new column beside value 2 with the average.



The output needs to look like:



value 1         value 2        avg
1 10 nan
4 1 2.5
5 8 4.5
6 10 5.5
10 12 8.0
.
.


How would I go about doing this?







python python-3.x python-2.7 pandas dataframe






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asked Nov 16 '18 at 0:23









HelloToEarthHelloToEarth

515215




515215













  • It all depends on how the data is represented. Do you have a list? A list of lists? Try to explain it in the question and add an example of what you tried so far.

    – Marco Bonelli
    Nov 16 '18 at 0:27



















  • It all depends on how the data is represented. Do you have a list? A list of lists? Try to explain it in the question and add an example of what you tried so far.

    – Marco Bonelli
    Nov 16 '18 at 0:27

















It all depends on how the data is represented. Do you have a list? A list of lists? Try to explain it in the question and add an example of what you tried so far.

– Marco Bonelli
Nov 16 '18 at 0:27





It all depends on how the data is represented. Do you have a list? A list of lists? Try to explain it in the question and add an example of what you tried so far.

– Marco Bonelli
Nov 16 '18 at 0:27












1 Answer
1






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oldest

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3














shift



You can sum a series with the shifted version of itself:



df['avg'] = (df['value1'] + df['value1'].shift()) / 2

print(df)

value1 value2 avg
0 1 10 NaN
1 4 1 2.5
2 5 8 4.5
3 6 10 5.5
4 10 12 8.0





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    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    3














    shift



    You can sum a series with the shifted version of itself:



    df['avg'] = (df['value1'] + df['value1'].shift()) / 2

    print(df)

    value1 value2 avg
    0 1 10 NaN
    1 4 1 2.5
    2 5 8 4.5
    3 6 10 5.5
    4 10 12 8.0





    share|improve this answer




























      3














      shift



      You can sum a series with the shifted version of itself:



      df['avg'] = (df['value1'] + df['value1'].shift()) / 2

      print(df)

      value1 value2 avg
      0 1 10 NaN
      1 4 1 2.5
      2 5 8 4.5
      3 6 10 5.5
      4 10 12 8.0





      share|improve this answer


























        3












        3








        3







        shift



        You can sum a series with the shifted version of itself:



        df['avg'] = (df['value1'] + df['value1'].shift()) / 2

        print(df)

        value1 value2 avg
        0 1 10 NaN
        1 4 1 2.5
        2 5 8 4.5
        3 6 10 5.5
        4 10 12 8.0





        share|improve this answer













        shift



        You can sum a series with the shifted version of itself:



        df['avg'] = (df['value1'] + df['value1'].shift()) / 2

        print(df)

        value1 value2 avg
        0 1 10 NaN
        1 4 1 2.5
        2 5 8 4.5
        3 6 10 5.5
        4 10 12 8.0






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 16 '18 at 0:31









        jppjpp

        102k2165115




        102k2165115
































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