minutes.py

import os
import re

with open('sept record.csv', 'r') as records:
    minutes = 0.0
    for line in records:
        match = re.search("(\d+):(\d+)", line)
        if match:
            duration = int(match.group(1)) * 60 + int(match.group(2))
            minutes += duration
    print float(minutes) / 60