【卷一】正则表达式一

正则表达式一般是爬虫用的，下面我们就通过一题多解来学习下正则表达式

参考:《Python核心编程(3rd)》—P33

 1 # coding: utf-8
 2
 3 import re
 4
 5 data = """
 6 System                           4 Services                   0        388 K
 7 smss.exe                       408 Services                   0      1,440 K
 8 System Idle Process              0 Services                   0         24 K
 9 """
10
11 data = data.split("\n")
12
13 for i in data:
14     # (?: )与 ‘|‘
15     print re.findall(r"((?:\w+.)+)\s\s+(\d+) \w+\s\s+\d\s\s+(\d+ K|\d+,\d+ K)", i)
16     # (?: )与 ‘(?:|)‘
17     #print re.findall(r"((?:\w+.)+)\s\s+(\d+) \w+\s\s+\d\s\s+((?:\d+|\d+,\d+) K)", i)
18     # (?: )与 ‘[]‘
19     #print re.findall(r"((?:\w+.)+)\s\s+(\d+) \w+\s\s+\d\s\s+([\d+,]+ K)", i)
20     

展开

结果如下:

我们来解释下(?:)的用法,大家再看一下下面的例子，就清楚下