如何在python中使用正则表达式查找两个非字母数字字符之间的模式

Question

I am very new to python regex. i am not able to get a clear idea about how to search for " * " in a sentence , since * is used as a keyword in regex i am getting confused. my question is , i have a file in which :

*CHI:   <that guy was> [//] that bunny was going to [: gonna] take that
    balloon !
%mor:   pro:dem|that n|bunny aux|be&PAST&13S part|go-PRESP
    part|go-PRESP~inf|to v|take pro:dem|that n|balloon !

So in this i have to retrieve the sentence that is between "*CHI :" and "%mor"

my desired output should be

<that guy was> [//] that bunny was going to [: gonna] take that
        balloon !

Answer 1

You can use the re.DOTALL flag to make . match newlines; there's no need for lookarounds:

import re

s = '''*CHI:   <that guy was> [//] that bunny was going to [: gonna] take that
    balloon !
%mor:   pro:dem|that n|bunny aux|be&PAST&13S part|go-PRESP
    part|go-PRESP~inf|to v|take pro:dem|that n|balloon !
'''

print(re.search(r'\*CHI:   (.+)\n%mor:', s, re.DOTALL)[1])

Output:

<that guy was> [//] that bunny was going to [: gonna] take that
    balloon !

Try it out

Answer 2

You can put * inside []. Inside the character class [] the metachars like *
are stripped of the special meaning.

['*']

with re.search

t = """*CHI:   <that guy was> [//] that bunny was going to [: gonna] take that
    balloon !
%mor:   pro:dem|that n|bunny aux|be&PAST&13S part|go-PRESP
    part|go-PRESP~inf|to v|take pro:dem|that n|balloon !
 """

mo = re.search(r'[*]CHI:\s+(.*)\s+%mor:', t, re.S)

mo.group(1)

'<that guy was> [//] that bunny was going to [: gonna] take that\n    balloon !'

With re.findall

re.findall(r'[*]CHI:\s+(.*)\s+%', t,re.S)  

['<that guy was> [//] that bunny was going to [: gonna] take that\n    balloon !']

Answer 3

Escape the '*' character:

re.findall(r'(?<=\*CHI:)[\s\S]*(?=%mor:)', s)

The positive lookbehind '?<=' and positive lookahead '?=' will trim your start and end terms. [\\s\\S] will take care of newline characters.