Is it worth using Python's re.compile?

Question

Is there any benefit in using compile for regular expressions in Python?

h = re.compile(\'hello\')
h.match(\'hello world\')

vs

Answer 1

This answer might be arriving late but is an interesting find. Using compile can really save you time if you are planning on using the regex multiple times (this is also mentioned in the docs). Below you can see that using a compiled regex is the fastest when the match method is directly called on it. passing a compiled regex to re.match makes it even slower and passing re.match with the patter string is somewhere in the middle.

>>> ipr = r'\D+((([0-2][0-5]?[0-5]?)\.){3}([0-2][0-5]?[0-5]?))\D+'
>>> average(*timeit.repeat("re.match(ipr, 'abcd100.10.255.255 ')", globals={'ipr': ipr, 're': re}))
1.5077415757028423
>>> ipr = re.compile(ipr)
>>> average(*timeit.repeat("re.match(ipr, 'abcd100.10.255.255 ')", globals={'ipr': ipr, 're': re}))
1.8324008992184038
>>> average(*timeit.repeat("ipr.match('abcd100.10.255.255 ')", globals={'ipr': ipr, 're': re}))
0.9187896518778871