Python中的负RegEx模式匹配等效于Perl（！〜运算符）

debugcn 发表于 Dev

加菲猫

有什么办法可以对我使用的正则表达式进行完全反向匹配。

(?!...)仅适用于简单模式。我的意思是我有一个RegEx可以匹配多种格式，但是我想替换字符串中除多种格式外的所有内容。

举例来说：我编写了一个复杂的RegEx模式来查找工作日，小时，月，年。而不是找到这些匹配项，而是使用这些模式来分割字符串并加入所有匹配项；如果存在逆向匹配，我可以单次替换。

例子

hr = """
Monday: 11:30am - 9:30pm Tuesday: 11:30am - 9:30pm
Wednesday: 11:30am - 10:00pm Thursday: 11:30am - 10:00pm 
Friday: 11:30am - 10:30pm Saturday: 11:00am - 10:30pm
(brunch served until 3pm) Sunday: 10:30am - 9:30pm (brunch served until 3pm)
Happy Hour and Special Appetizer menu starting at $3 in the bar. Hours from 4 - 7pm Daily.
$4 BURGER special available on Monday. Wednesday: 1/2 off all bottled wines (4-close)"""


import re

newStr = []
dayPattern = """
   (?:mon|tue|wed|thu|fri|sat|sun|thurs)(?:day)?(?:[.:])*
   \s*
   (?:\d{1,2}(?:[:]\d{1,2})?)\s*(?:[ap][.]?m.?) # Start hour
   \s*[-|to]+\s*
  (?:\d{1,2}(?:[:]\d{1,2})?)\s*(?:[ap][.]?m.?) # Close   hour
 """

newStr.extend(\
    re.findall(re.compile(dayPattern, re.VERBOSE|re.IGNORECASE), hr))

print " ".join(newStr)

输出

Monday: 11:30am - 9:30pm  Thursday: 11:30am - 10:00pm  Friday: 11:30am - 10:30pm  Sunday: 10:30am - 9:30pm

但是我在这里失踪了"Monday: 11:30am - 9:30pm Tuesday: 11:30am - 9:30pm Wednesday: 11:30am - 10:00pm Thursday: 11:30am - 10:00pm Friday: 11:30am - 10:30pm"。

我可以修改我的正则表达式以也包括此模式

但是除了这样，我可以删除星期一/星期二/ ...，周一/周二/周三和11:00 am/12pm以外的任何单词。

即，正是我想要的是此输出： Monday: 11:30am - 9:30pm Tuesday: 11:30am - 9:30pm Wednesday: 11:30am - 10:00pm Thursday: 11:30am - 10:00pm Friday: 11:30am - 10:30pm Saturday: 11:00am - 10:30pm Sunday: 10:30am - 9:30pm

比雷

我不明白您打算进行反向正则表达式的意图。findall()似乎是一种选择时间的自然方法，例如：

' '.join(re.findall(r'\w{3,6}day:\s*\d{1,2}:\d{1,2}[ap]m\s*-\s*\d{1,2}:\d{1,2}[ap]m', hr))

它产生：

'Monday: 11:30am - 9:30pm Tuesday: 11:30am - 9:30pm Wednesday: 11:30am - 10:00pm Thursday: 11:30am - 10:00pm Friday: 11:30am - 10:30pm Saturday: 11:00am - 10:30pm Sunday: 10:30am - 9:30pm'

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