Split pandas dataframe into multiple dataframes with equal numbers of rows

Question

I have a dataframe df :

        a              b          c
0   0.897134    -0.356157   -0.396212
1   -2.357861   2.066570    -0.512687
2   -0.0         


        

Answer 1

There are many ways to do what you want, your method looks over-complicated. A groupby using a scaled index as the grouping key would work:

df = pd.DataFrame(data=np.random.rand(100, 3), columns=list('ABC'))
groups = df.groupby(np.arange(len(df.index))/10)
for (frameno, frame) in groups:
    frame.to_csv("%s.csv" % frameno)

Answer 2

You can use a dictionary comprehension to save slices of the dataframe in groups of ten rows:

df_dict = {n: df.iloc[n:n+10, :] 
           for n in range(0, len(df), 10)}

>>> df_dict.keys()
[0, 10, 20]

>>> df_dict[10]
           a         b         c
10 -0.011909 -0.304162  0.422001
11  0.127570  0.956831  1.837523
12 -1.074771  0.379723 -1.889117
13 -1.449475 -0.799574 -0.878192
14 -1.029757  0.551023  2.519929
15 -1.001400  0.838614 -1.006977
16  0.677216 -0.403859  0.451338
17  0.221596 -0.323259  0.324158
18 -0.241935 -2.251687 -0.088494
19 -0.995426  0.665569 -2.228848