Python re (regex) match examples

Python regular expression module (re) can be used to check a string begins with a pattern using re.match(). Note that it is different from re.search() as it matches pattern from the beginning. Basic usage of re.match() is:

re.match(pattern, string, flags=0)

Here are some examples.

re.match – ignore case

We can use flag re.I (or re.IGNORECASE) for ignoring case.

import re
m = re.match('hello', "Hello WORLD", re.I)
if (m):
  print m.group()

Hello

re.match – with sub groups

Round brackets in pattern can be used for subgroups matching and can be accessed using m.groups().

import re
m = re.match('(hello)\s+(world)', "Hello WORLD test", re.I)
if (m):
  print m.group()
  print m.groups()

Hello WORLD
('Hello', 'WORLD')