Getting text between one or more pairs of strings using regex in python-CodePudding

I'm trying to get a string between one or more pairs of string. For example,

import re
string1 = 'oi sdfdsf a'
string2 = 'biu serdfd e'
pattern = '(oi|biu)(.*?)(a|e)'
substring = re.search(pattern, string1).group(1)

In this case I should get: "sdfdsf" if I use string1 and "serdfd" if I use string2 in the search funnction. Instead I'm getting "oi" or "biu"

CodePudding user response：

If you use string in parentheses, regex will capture your string. If you want capture some strings but not match of them, you should add '(?:)' expressions.

You can just changed your pattern as below.

pattern = '(?:oi|biu)[ /t] ([\w*] )[ /t] (?:a|e)'

CodePudding user response：

You are placing capture groups around parts of your regex pattern which you don't really want to capture. Consider this version:

inp = ['oi sdfdsf a', 'biu serdfd e']
for i in inp:
    word = re.findall(r'\b(?:oi|biu) (\S ) (?:a|e)\b', i)[0]
    print(i   ' => '   word)

Here we turn off the capture groups on the surrounding words on the left and right, and instead use a single capture group around the term you want to capture. This prints:

oi sdfdsf a => sdfdsf
biu serdfd e => serdfd