Splitting CSV Files in Python

import pandas as pd

#csv file name to be read in 

in_csv = 'input.csv'

#get the number of lines of the csv file to be read

number_lines = sum(1 for row in (open(in_csv)))

#size of rows of data to write to the csv, 

#you can change the row size according to your need

rowsize = 500

#start looping through data writing it to a new file for each set

for i in range(1,number_lines,rowsize):

    df = pd.read_csv(in_csv,

          header=None,

          nrows = rowsize,#number of rows to read at each loop

          skiprows = i)#skip rows that have been read

    #csv to write data to a new file with indexed name. input_1.csv etc.

    out_csv = 'input' + str(i) + '.csv'

    df.to_csv(out_csv,

          index=False,

          header=False,

          mode='a',#append data to csv file

          chunksize=rowsize)#size of data to append for each loop