Detailed explanation of Python's example of extracting specified content based on regular expressions

python Extract specified content based on regular expression

Regular expressions are extremely powerful, It is very convenient to use regular expressions to extract the desired content.

The following demonstrates how to extract content that meets the requirements through regular expressions in python.

Example code:

import re 
# 　　正则表达式是极其强大的，利用正则表达式来提取想要的内容是很方便的事。 
# 下面演示了在python里，通过正则表达式来提取符合要求的内容。有几个要注意 
# 的地方就是： 
# [1] 要用()将需要的内容包含起来 
# [2] 编号为0的group是整个符合正则表达式的内容，编号为1的是第一个(及对应 
#   的)包含的内容 
# @param regex: regular expression, use () to group the result 
#   正则表达式，用()将要提取的内容包含起来 
# @param content:  
# @param index: start from 1, depends on the \p regex's () 
#   从1开始，可以通过数(来得到，其中0是全部匹配 
# @return: the first match of the \p regex 
#   只返回第一次匹配的内容 
def extractData(regex, content, index=1): 
  r = '0' 
  p = re.compile(regex) 
  m = p.search(content) 
  if m: 
    r = m.group(index) 
  return r 
 
regex = r'第(.*)场雪' 
content = '2002年的第一场雪' 
index = 1 
print extractData(regex, content, index)

Thank you for reading, I hope it can help everyone, thank you for your support of this site!

The above is the detailed content of Detailed explanation of Python's example of extracting specified content based on regular expressions. For more information, please follow other related articles on the PHP Chinese website!