RegEx Python not working

Question

My Reg-Ex pattern is not working, why?

string = "../../example/tobematched/nonimportant.html"
pattern = "example\/([a-z]+)\/"
test = re.match(pattern, string)
# None

http://www.regexr.com/39mpu

match will only match the beginning of the string. Replace match with search — Vincent Beltman, Oct 13 '14 at 14:03
Yes, `match` is perhaps the most ill-designed function in python. — georg, Oct 13 '14 at 14:11

score 3 · Answer 1 · answered Oct 13 '14 at 14:09

re.match() matches from the beginning of the string, you need to use re.search() which looks for the first location where the regular expression pattern produces a match and returns a corresponding MatchObject instance.

>>> import re
>>> s = "../../example/tobematched/nonimportant.html"
>>> re.search(r'example/([a-z]+)/', s).group(1)
'tobematched'

score 2 · Answer 2 · edited Oct 13 '14 at 14:09

2

Try this.

test = re.search(pattern, string)

Match matches the whole string from the start, so it will give None as the result.

Grab the result from test.group().

edited Oct 13 '14 at 14:09

Burhan Khalid

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answered Oct 13 '14 at 14:04

vks

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score 1 · Accepted Answer · answered Oct 13 '14 at 14:11

To give you the answer in short:

search ⇒ finds something anywhere in the string and return a match object.

match ⇒ finds something at the beginning of the string and return a match object.

That is the reason you have to use

foo = re.search(pattern, bar)

RegEx Python not working

3 Answers3