extract windowed data from pandas dataframe efficiently












0















let say i have a DataFrame with two columns as follow



 1. 'a'    0.1
2. 'b' 0.2
3. 'c' 0.3
4. 'd' 0.4


and i want to extract 'windowed data' from it as follows :
(window size : 2)



[['a'    0.1], ['b'    0.2]], [['b'    0.2], ['c'    0.3]], [['c'    0.3], ['d'    0.4]]


currently, im using the simplest way with loop like this :



[df.loc[i - window_size : i, features].values for i in target_data_idx]


since im handling almost 1000k data, this procedure requires huge runtime



is there any better solution for this using parallel ways(like Dask framework)?










share|improve this question





























    0















    let say i have a DataFrame with two columns as follow



     1. 'a'    0.1
    2. 'b' 0.2
    3. 'c' 0.3
    4. 'd' 0.4


    and i want to extract 'windowed data' from it as follows :
    (window size : 2)



    [['a'    0.1], ['b'    0.2]], [['b'    0.2], ['c'    0.3]], [['c'    0.3], ['d'    0.4]]


    currently, im using the simplest way with loop like this :



    [df.loc[i - window_size : i, features].values for i in target_data_idx]


    since im handling almost 1000k data, this procedure requires huge runtime



    is there any better solution for this using parallel ways(like Dask framework)?










    share|improve this question



























      0












      0








      0








      let say i have a DataFrame with two columns as follow



       1. 'a'    0.1
      2. 'b' 0.2
      3. 'c' 0.3
      4. 'd' 0.4


      and i want to extract 'windowed data' from it as follows :
      (window size : 2)



      [['a'    0.1], ['b'    0.2]], [['b'    0.2], ['c'    0.3]], [['c'    0.3], ['d'    0.4]]


      currently, im using the simplest way with loop like this :



      [df.loc[i - window_size : i, features].values for i in target_data_idx]


      since im handling almost 1000k data, this procedure requires huge runtime



      is there any better solution for this using parallel ways(like Dask framework)?










      share|improve this question
















      let say i have a DataFrame with two columns as follow



       1. 'a'    0.1
      2. 'b' 0.2
      3. 'c' 0.3
      4. 'd' 0.4


      and i want to extract 'windowed data' from it as follows :
      (window size : 2)



      [['a'    0.1], ['b'    0.2]], [['b'    0.2], ['c'    0.3]], [['c'    0.3], ['d'    0.4]]


      currently, im using the simplest way with loop like this :



      [df.loc[i - window_size : i, features].values for i in target_data_idx]


      since im handling almost 1000k data, this procedure requires huge runtime



      is there any better solution for this using parallel ways(like Dask framework)?







      python pandas parallel-processing






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 21 '18 at 14:34









      Naga Kiran

      2,3971617




      2,3971617










      asked Nov 21 '18 at 14:01









      김동규김동규

      313




      313
























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