【8.5】生成器如何读取大文件

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 
 5 def MyReadLines(f, newline):
 6     buf = ''
 7     while True:
 8         while newline in buf:
 9             pos = buf.index(newline)
10             yield buf[:pos]
11             buf = buf[pos + len(newline):]
12         chunk = f.read(4096*10)
13         if not chunk:
14             # 说明已经读到了文件结尾，处理最后一条数据
15             yield buf
16             break
17         buf += chunk
18 
19 
20 with open('read_file.txt') as f:
21     for line in MyReadLines(f, '{|}'):
22         print(line)

asdjkhaskjfdhaskhd
 asdjalskhdkjashgkdyoias
 asdjaslhdiasghfou
 wiuqoxgsabjkdg
 ashdoqwhdasjdha
 as;djoqwhdohqwodhg

　　文件中的数据，一行且很大

1 with open(filePath) as f:
2     for line in f:
3         print(line)
4         # Processing data

　　文件数据大，但是多行