Regex - matching without trailing second decimal and digits

My task is to find lines on a text file that match the following pattern: "SMC" followed by a space, 1-3 digits, period, and 1-3 digits. My issue: It's also returning digits after the second period/decimal.

import re

with open("caosDump.txt", 'r', encoding="cp1252") as inp, open("newCaosDump.txt", 'w') as output:
    for line in inp:
        if re.search(r'SMC\s\d{1,3}\.\d{1,3}', line):
            output.write(line)

I have tried many things such as positive/negative lookahead, word boundary, etc. but nothing worked. Adding ^ and $ break the code.

It’s also returning the lines that contain SMC 14.08.040, but I don’t want to include these lines on my new text file. (Note: Using Python)

You need to add a negative lookahead like this:

if re.search(r'SMC\s\d{1,3}\.\d{1,3}(?!\.?\d)', line):

The (?!\.?\d) lookahead will fail a match when the last 1-3 digits are immediately followed with a . or .+digit.

Note that the \b after SMC is redundant as you require a whitespace after the word. If SMC must be matched as a whole word, \b must be placed immediately before the word, i.e. r'\bSMC\s\d{1,3}\.\d{1,3}(?!\.?\d)'.

If there can be more than one whitespace after SMC word, use \s+ instead of \s.

See the regex demo.