Find first x matches with re.findall

Question

I need limit re.findall to find first 3 matches and then stop.

for example

text = 'some1 text2 bla3 regex4 python5'
re.findall(r'\d',text)

then I get:

['1', '2', '3', '4', '5']

and I want:

['1', '2', '3']

You can take a look here: http://stackoverflow.com/questions/16235770/how-to-limit-regexs-findall-method — Casimir et Hippolyte, Apr 20 '14 at 17:19
or better here : http://stackoverflow.com/questions/11902378/python-regular-expressions-limit-results — Casimir et Hippolyte, Apr 20 '14 at 17:25

score 10 · Answer 1 · edited May 23 '17 at 12:09

10

re.findall returns a list, so the simplest solution would be to just use slicing:

>>> import re
>>> text = 'some1 text2 bla3 regex4 python5'
>>> re.findall(r'\d', text)[:3]  # Get the first 3 items
['1', '2', '3']
>>>

edited May 23 '17 at 12:09

Community

answered Apr 20 '14 at 17:15

score 8 · Accepted Answer · answered Apr 20 '14 at 17:19

8

To find N matches and stop, you could use re.finditer and itertools.islice:

>>> import itertools as IT
>>> [item.group() for item in IT.islice(re.finditer(r'\d', text), 3)]
['1', '2', '3']

answered Apr 20 '14 at 17:19

unutbu

2 Answers2