How to set ignorecase flag for part of regular expression in Python?

Question

Is it possible to implement in Python something like this simple one:

#!/usr/bin/perl
my $a = \'Use HELLO1 code\';
if($a =~ /(?i:use)\\s+([A-Z0-9]+)\\s+(?i:c         


        

Answer 1

As far as I could find, the python regular expression engine does not support partial ignore-case. Here is a solution using a case-insensitive regular expression, which then tests if the token is uppercase afterward.

#! /usr/bin/env python

import re

token_re = re.compile(r'use\s+([a-z0-9]+)\s+code', re.IGNORECASE)
def find_token(s):
    m = token_re.search(s)
    if m is not None:
        token = m.group(1)
        if token.isupper():
            return token

if __name__ == '__main__':
    for s in ['Use HELLO1 code',
              'USE hello1 CODE',
              'this does not match',
             ]:
        print s, '->',
        print find_token(s)

Here is the program's output:

Use HELLO1 code -> HELLO1
USE hello1 CODE -> None
this does not match -> None