Python / RegEx / findall：如何从比赛后面提取模式？

Question

I did look into lookbehind pattern (?<=...) but this doesn't seem to save the match.

input:

aaaaaaGET(abc)aaaaaa
aaaaaaaaaaaaa
aaaaaMATCH(00)aaaaaaa
aaaaaaaaaaaaa
aaaaGEX(xyz)aaaaaa
aaaaaaGET(notneed)aaaaaa
aaaaaaGEX(no)aaaaaa
aaaaaaGET(nope)aaaaaa
aaaaaaGET(AbC)aaaaaa
aaaaaaaaaaaaa
aaaaaaaaaaaaa
aaaaaMATCH(01)aaaaaaa
aaaaaaaaaaaaa
aaaaGEX(XYz)aaaaaa

output:

[(abc, 00, xyz), (AbC, 01, XYz]

I want use re.findall to find all the MATCH parts, and then what follows both GET (above the match) and GEX (below the match), but I can't figure out how to get anything like that from behind.

If all my related matches were ahead of MATCH, I'd have something like

re.findall('MATCH\((\d*)\).*?GEX\(([A-Za-z]*)\)', text, re.DOTALL)

But not sure how to get back and get the GET value

Answer 1

I think you want something like this,

>>> import re
>>> s = """aaaaaaGET(abc)aaaaaa
... aaaaaaaaaaaaa
... aaaaaMATCH(00)aaaaaaa
... aaaaaaaaaaaaa
... aaaaGEX(xyz)aaaaaa
... aaaaaaGET(notneed)aaaaaa
... aaaaaaGEX(no)aaaaaa
... aaaaaaGET(nope)aaaaaa
... aaaaaaGET(AbC)aaaaaa
... aaaaaaaaaaaaa
... aaaaaaaaaaaaa
... aaaaaMATCH(01)aaaaaaa
... aaaaaaaaaaaaa
... aaaaGEX(XYz)aaaaaa"""
>>> m = re.findall(r'GET.*?\(([^)]*)\)(?:(?!GET|GEX).)*?\(([^)]*)\)(?:(?!GET|GEX).)*?GEX\(([^)]*)\)', s, re.DOTALL)
>>> m
[('abc', '00', 'xyz'), ('AbC', '01', 'XYz')]

(?:(?!GET|GEX).)* negative lookahead checks for following three characters not to be GET or GEX , if it is not present, then only it matches the next character.