python regex) pattern '\d-\d' with string '1-4-1'

Asked Oct 24 '19 at 08:35

Active Oct 24 '19 at 08:35

Viewed 29 times

I have a quick question as my code below:

import re

s = '1-4-1'
p = '\d-\d'
re.findall(p,s)

>> ['1-4']
>> but what I expected is: ['1-4', '4-1']

I have no idea why the pattern cannot catch '4-1'

asked Oct 24 '19 at 08:35

Roy

3

`\d-\d` already matched and consumed `4`, the engine only starts to search for the next match after the previous match. – Wiktor Stribiżew Oct 24 '19 at 08:37
2

Try `(?=(\d-\d))` it should grab the group match. – OrderAndChaos Oct 24 '19 at 08:40
1

Try the following `>>>import regex as re>>>s = '1-4-1'>>>matches = re.findall(r'\d-\d', s, overlapped=True)` – Kostas Charitidis Oct 24 '19 at 08:43
@WiktorStribiżew I haven't heard the word 'consume' in regex before. I will search it. Thanks. – Roy Oct 24 '19 at 08:49
It means the text was matched and appended to a match value, and the regex index got moved after this text. – Wiktor Stribiżew Oct 24 '19 at 08:50
@WiktorStribiżew I see, so the pattern won't be re-used. – Roy Oct 24 '19 at 08:53

0 Answers0