Regex not working...

Question

import re

pattern = r"^\d{2}[\.-]\d{2}[\.-]\d{4}\s \d{2}[\.:]\d{2}[\.:]\d{2}"

match = re.match(pattern, "01-01-1977 12:56:33")
if match:
print("Match 1")

match = re.match(pattern, "2-29-2012 3:30:33")
if match:
print("Match 2")

match = re.match(pattern, " ! $?")
if match:
print("Match 3")

Answer 1

I see what it is. Your pattern is what's wrong...

"\s \d"

That portion is the culprit. \s allows 1 tab, space,new line etc but in your string you added spaces of your own. So it's looking for a newline/tab/space followed by another 4 spaces. Remember spaces in your Regex String counts too.

How to fix this?

pattern = r"^\d{2}[\.-]\d{2}[\.-]\d{4}\s\d{2}[\.:]\d{2}[\.:]\d{2}"

# I swear typing Regex is a pain in the arse.
# :^)

Answer 2

Hi Dennis,

depending on how strict you wish to be, you could also use match.search instead of match.match and using groups to the portions you desire and using ".*?" in between, what could be one or more different characters.

pattern = re.compile('(\d{1,2}[\.-]\d{1,2}[\.-]\d{4}).*?(\d{1,2}[\.:]\d{1,2}[\.:]\d{1,2})')
match = pattern.search("2-29-2012 3:30:33")
date = match.group(1)
time = match.group(2)

I changed the code a little bit, to work with 1 or 2 digits in the dates and times.

hope this helps.

Answer 3

Thanks Don! extra 4 spaces threw me off;)