Credit Card type detection

cctype.py

#!/usr/bin/python

import re

def cctype(number):
    cclist = {
        'Mastercard': re.compile('^(?:5[1-5][0-9]{2}|222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12}$'),
        'Visa': re.compile('^4[0-9]{12}(?:[0-9]{3})?$'),
        'American Express': re.compile('^3[47][0-9]{13}$'),
        'Diners Club': re.compile('^3(?:0[0-5]|[68][0-9])[0-9]{11}$'),
        'Discover': re.compile('^6(?:011|5[0-9]{2})[0-9]{12}$')
    }

    for cc in cclist:
        if cclist[cc].match(number):
            return cc
    return None

import sys
if __name__ == "__main__":
  '''Specify credit card on command-line to get type'''
    print(str(cctype(sys.argv[1])))

Special thanks to https://www.regexbuddy.com/library.html