Python regular expression capture re-use

Question

I'm trying to create a Python regular expression that will match a string if and only if that string begins and ends with the same lower-case letter. The following seems like it ought to work, but matches every string:

(?P<st>[a-z]).*(?P=st)$

Any suggestions will be appreciated.

vks · Accepted Answer · 2015-05-09 05:37:19Z

3

^([a-z]).*\1$

This will require back reference.See demo.

https://regex101.com/r/iV6mP5/5#python

import re
p = re.compile(r'^([a-z]).*\1$', re.MULTILINE)
test_str = "a sdf sd fdsf sd a\nsdfdsf ASDSDSAD@#$@#ASDASDs\nsadasd Wdsda"

re.findall(p, test_str)

edited May 9, 2015 at 5:37

answered May 9, 2015 at 5:26

vks

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Comments

Stefan Pochmann · Accepted Answer · 2015-05-09 12:33:31Z

0

I realize you asked for a regex, but then again, so many people ask that because they somehow think that's the only way to do these things.

>>> for s in ('test', 'foo', 'Test', ''):
    if s and s[0].islower() and s[0] == s[-1]:
        print('good:', s)

good: test

answered May 9, 2015 at 12:33

Stefan Pochmann

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