python - Split dataframe into relatively even chunks according to length

Question

I have to create a function which would split provided dataframe into chunks of needed size. For instance if dataframe contains 1111 rows, I want to be able to specify chunk size of 400 rows, and get three smaller dataframes with sizes of 400, 400 and 311. Is there a convenience function to do the job? What would be the best way to store and iterate over sliced dataframe?

Example DataFrame

import numpy as np
import pandas as pd

test = pd.concat([pd.Series(np.random.rand(1111)), pd.Series(np.random.rand(1111))], axis = 1)

Answer 1

You can take the floor division of a sequence up to the amount of rows in the dataframe, and use it to groupby splitting the dataframe into equally sized chunks:

n = 400
for g, df in test.groupby(np.arange(len(test)) // n):
    print(df.shape)
# (400, 2)
# (400, 2)
# (311, 2)