Question

Program Set 2 10 points) Credit card number validation Program Credit card numbers follow certain patterns: It must have between 13 and 16 digits, and the number must start with: 4 for Visa cards 5 for MasterCard credit cards 37 for American Express cards 6 for Discover cards In 1954, Hans Luhn of IBM proposed an algorithm for validating credit card numbers. The algorithm is useful to determine whether a card number is entered correctly or whether a credit card is scanned correctly by a scanner. Credit card numbers are generated following this validity check, commonly known as the Luhn check or the Mod 10 check, which can be described as follows (for illustration, consider the card number 4388576018402626): 1. Double every second digit from right to left. If doubling of a digit results in a two-digit number, add up the two digits to get a single-digit number. 438857601810226 2.3=4 4.2 -1.2-2 6.2 - 12 (1-2-3) 5.2 = 10 (1 +0=1) 8.2-16 (16-7) 4.28 2. Now add all single-digit numbers from Step 1. 4 + 4 + 8 + 2+ 3+ 1 + 7 + 8 = 37 3. Add all digits in the odd places from right to left in the card number. 6+6+0+ 8 + 0 + 7 + 8 + 3 = 38 4. Sum the results from Steps 2 and 3. 37. 38 - 75 5. If the result from Step 4 Is divisible by 10, the card number is valid; otherwise, it is invalid. For example, the number 4388576018402626 is invalid, but the number 4388576018410707 is valid. Write a program that prompts the user to enter a credit card number as a STRING. Allow the user enter multiple credit numbers to test for validity for each test case run(use a for loop) Prompt the user for how many credit card numbers he/she wants to check. You are to use the two credit card numbers provided in the sample output given below plus other credit card numbers using credit numbers that starts with 5, 37, and 6. Make sure you test at least 10 credit card numbers. Display whether the number is valid or invalid. Design your program to use the following functions (include type annotations, you must only use the functions template provided. You are not allowed to add extra functions or remove any of the functions that are provided)

Answer 1

def getDigit(n):
    n=str(n)
    if len(n)==2:
        n1=int(n[0])+int(n[1])
        return int(n1)
    else:
        return int(n)
def sumOfDoubleEvenPlace(leven):
    sum1=0
    for i in leven:
        x=int(i)
        sum1=sum1+getDigit(2*x)
    return sum1
def sumOfOddPlace(lodd):
    sum2=0
    for i in lodd:
        sum2=sum2+int(i)
    return sum2
def isvalid(number):
    lodd=number[::-2]
    leven=number[len(number)-2::-2]
    result=sumOfDoubleEvenPlace(leven)+sumOfOddPlace(lodd)
    if result%10==0:
        return True
    else:
        return False
def main():
    t=int(input("How many credit card numbers do you want to check?"))
    while t>0:
        number=input("Enter a credid card number as a long integer")
        if isvalid(number)==True:
            print(number+" is valid")
        else:
            print(number+" is invalid")
        t=t-1
main()