Python：正则表达式单词匹配

Posted 2023-03-29

【中文标题】Python：正则表达式单词匹配

【英文标题】：Python: regular expressions word match

【发布时间】：2015-10-13 06:31:44

【问题描述】：

我已经编写了这个小脚本，但我无法让 re.search 功能正常工作。我试图只匹配确切的单词（笑话），但 elif 语句不断返回打印，因为它在句子变量中找到笑话（来自小丑）。有没有办法让它计算单词笑话中的字母数量，所以只有当笑话是一个独立的词时它才是正确的？

#!/usr/bin/python
import re

sentence = 'The substantial treat shouts with the jokers'
find_emergency = re.search( r'emergency', sentence, re.M|re.I)
find_joke = re.search( r'joke', sentence, re.M|re.I)

if find_emergency :
   print 'Do you want to set this email as urgent?'
elif find_joke :  
  print "Do you want to mark this email as non-urgent?"
else :
   print "Sorry, we couldn\'t find what you were looking for ;("

【参考方案1】：

find_joke = re.search( r'\bjoke\b', sentence, re.M|re.I)

为此使用\b 或word boundary。

【讨论】：

谢谢@vks - 这正是我想要的

【参考方案2】：

您可以使用 vks 建议的单词边界方法。

或者您可以使用“in”关键字执行基本搜索。

#!/usr/bin/python
import re

sentence = 'The substantial treat shouts with the jokers'

if 'emergency' in sentence :
   print 'Do you want to set this email as urgent?'
elif 'joke' in sentence :  
  print "Do you want to mark this email as non-urgent?"
else :
   print "Sorry, we couldn\'t find what you were looking for ;("

【讨论】：

仍然会匹配joker i.e)"joke" in "i am a joker" True