CODEWITHSUNDEEP
pythonregexmatchdigits
Megastore
Megastore

Reputation: 73

Find regex match without a digit preceding the pattern

I am currently trying to extract dates from strings. Here are a few examples:

02.10 abcdef -> extract '02.10'
abcdef 03.12 -> extract '03.12'
abcdef 308.56 -> extract nothing

A simple regex such as (\d{2}.\d{2}) works fine for the first two cases but I catch a false positive for the third example, the regex returns 08.56, which makes sense.

Is there any way to prevent this string from being extracted? I tried [^0-9](\d{2}.\d{2}) which seems to be working on regex debugging websites but not when I compile it as a python regex with

import re
regex = re.compile(r'[^0-9](\d{2}.\d{2})')

Thanks in advance

Upvotes: 0

Views: 152

Answers (1)

E. Verdi
E. Verdi

Reputation: 320

I First thought you needed the complete number which is possible with: (\d*\.\d{2}) which returns 308.56

But then is saw the line:

Is there any way to prevent this string from being extracted? Which made me expect you want only two numbers, a dot and again two numbers. Otherwise the regex should return nothing.

Then the answer should be:

(?<![\w\d])(\d{2}\.\d{2})(?![\w\d])

You can test it on https://regex101.com/

enter image description here

Upvotes: 1

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