使用Python自动将一个CSV大文件分割成任意个小CSV文件

有时有必要将大文件拆分为小文件。在这篇简短的文章中，我将分享一个用Python编写的小脚本。也许您可以进一步开发它。但是，如果文件较大，则应谨慎使用代码中的循环。

假设您的输入文件名为input.csv。该代码会将其拆分为名称为input_1.csv，...，input_10.csv ....的新文件。

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 need11
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