credit-card-validator

Credit card numbers validation through python.

Details:

You and Fredrick are good friends. Yesterday, Fredrick received N credit cards from ABCD Bank. He wants to verify whether his credit card numbers are valid or not.
You happen to be great at regex so he is asking for your help! A valid credit card from ABCD Bank has the following characteristics:

• It must start with a 4, 5 or 6.

• It must contain exactly 16 digits.

• It must only consist of digits (0-9).

• It may have digits in groups of 4, separated by one hyphen "-".

• It must NOT use any other separator like ' ' , '_', etc.

• It must NOT have or more consecutive repeated digits. Valid Examples:

  4253625879615786 4424424424442444 5122-2368-7954-3214

InValid Examples:

    42536258796157867       #17 digits in card number → Invalid 
    4424444424442444        #Consecutive digits are repeating 4 or more times → Invalid
    5122-2368-7954 - 3214   #Separators other than '-' are used → Invalid
    44244x4424442444        #Contains non digit characters → Invalid
    0525362587961578        #Doesn't start with 4, 5 or 6 → Invalid

Input format: The first line of input contains an integer N. The next N lines contain credit card numbers.

Output Format

Print 'Valid' if the credit card number is valid. Otherwise, print 'Invalid'. Do not print the quotes.

Sample input:

    6
    4123456789123456
    5123-4567-8912-3456
    61234-567-8912-3456
    4123356789123456
    5133-3367-8912-3456
    5123 - 3567 - 8912 - 3456

Sample Output:

    Valid
    Valid
    Invalid
    Valid
    Invalid
    Invalid

Explanation

4123456789123456 : Valid
5123-4567-8912-3456 : Valid
61234-567-8912-3456 : Invalid, because the card number is not divided into equal groups of 4.
4123356789123456 : Valid
5133-6733-8912-3456 : Invalid, consecutive digits 3333 is repeating 4 times.
5123 - 4567 - 8912 - 3456 : Invalid, because space ' ' and - are used as separators.