Python regex match OR operator

Question

I\'m trying to match time formats in AM or PM.

i.e. 02:40PM
     12:29AM 

I\'m using the following regex

timePattern = re.compi         


        

Answer 1

It sounds like you're accessing group 1, when you need to be accessing group 0.

The groups in your regex are as follows:

\d{2}:\d{2}(AM|PM)
           |-----|  - group 1
|----------------|  - group 0 (always the match of the entire pattern)

You can access the entire match via:

timePattern.match('02:40PM').group(0)

Answer 2

Use a non capturing group (?: and reference to the match group.

Use re.I for case insensitive matching.

import re

def find_t(text):
    return re.search(r'\d{2}:\d{2}(?:am|pm)', text, re.I).group()

You can also use re.findall() for recursive matching.

def find_t(text):
    return re.findall(r'\d{2}:\d{2}(?:am|pm)', text, re.I)

See demo

Answer 3

Use a non-delimited capture group (?:...):

>>> from re import findall
>>> mystr = """
... 02:40PM
... 12:29AM
... """
>>> findall("\d{2}:\d{2}(?:AM|PM)", mystr)
['02:40PM', '12:29AM']
>>>

Also, you can shorten your Regex to \d\d:\d\d(?:A|P)M.

Answer 4

You're not capturing the Hour, minute fields:

>>> import re
>>> r = re.compile('(\d{2}:\d{2}(?:AM|PM))')
>>> r.search('02:40PM').group()
'02:40PM'
>>> r.search('Time is 12:29AM').group()
'12:29AM'

Answer 5

Are you accidentally grabbing the 1st cluster (the stuff in that matches the portion of the pattern in the parentheses) instead of the "0st" cluster (which is the whole match)?