python从txt文档中随机抽取n条记录 

 1 #coding:utf-8
 2 
 3 import random
 4 import time
 5 """
 6 注意盘符小写
 7 
 8 """
 9 f = open("d:\\MyData\\zhaohz4\\Desktop\\train.txt","r")           #源文件
10 fw = open("d:\\MyData\\zhaohz4\\Desktop\\sample_10.txt","w")     #待写文件
11 """
12 如下亦可
13 f = open("d:/MyData/zhaohz4/Desktop/train.txt","r")
14 fw = open("d:/MyData/zhaohz4/Desktop/sample_10.txt","w")
15 """
16 def test():  
17     start = time.clock()
18     raw_list = f.readlines()
19     random.shuffle(raw_list)
20     for i in range(50):                           #随机抽取数目 n
21         fw.writelines(raw_list[i])
22 
23     end = time.clock()
24     print("cost time is %f" %(end - start))
25 
26 if __name__ =="__main__":
27     test()

 

posted @ 2019-11-26 08:38  Parallax  阅读(773)  评论(0)    收藏  举报