python进行拆分大文件 使用python进行拆分大文件的方法

# -*- coding:utf-8 -*-
from datetime import datetime
 
def Main():
 source_dir = '/data/u_lx_data/zhangqm/sh/yanjie/liuxuesheng/jz_yuanshi_list0206.txt'
 target_dir = '/data/u_lx_data/zhangqm/sh/yanjie/liuxuesheng/split/'
 
 # 计数器
 flag = 0
 
 # 文件名
 name = 1
 
 # 存放数据
 dataList = []
 
 print("开始。。。。。")
 print(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))
 
 with open(source_dir,'r') as f_source:
  for line in f_source:
   flag+=1
   dataList.append(line)
   if flag == 2000000:
    with open(target_dir+"jz_yuanshi_list_"+str(name)+".txt",'w+') as f_target:
     for data in dataList:
      f_target.write(data)
    name+=1
    flag = 0
    dataList = []
    
 # 处理最后一批行数少于200万行的
 with open(target_dir+"jz_yuanshi_list_"+str(name)+".txt",'w+') as f_target:
  for data in dataList:
   f_target.write(data)
 
 print("完成。。。。。")
 print(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))
 
if __name__ == "__main__":
 Main()