Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 33

Python
1

Tell us what’s happening:

Learn How to Work With Numbers and Strings by Implementing the Luhn Algorithm - Step 33:

I don’t know what it means in the coding language to return true. When I only put semi-colon and go on, it doesn’t work. I feel like I am missing something in order for the translated_card_number to return true. I just need a hint regarding this. Thank you very much

Your code so far

def verify_card_number(card_number):
    sum_of_odd_digits = 0
    card_number_reversed = card_number[::-1]
    odd_digits = card_number_reversed[::2]

    for digit in odd_digits:
        sum_of_odd_digits += int(digit)

    sum_of_even_digits = 0
    even_digits = card_number_reversed[1::2]
    for digit in even_digits:
        number = int(digit) * 2
        if number >= 10:
            number = (number // 10) + (number % 10)
        sum_of_even_digits += number
    total = sum_of_odd_digits + sum_of_even_digits
    print(total)
    return total % 10 == 0

# User Editable Region

def main():
    card_number = '4111-1111-4555-1142'
    card_translation = str.maketrans({'-': '', ' ': ''})
    translated_card_number = card_number.translate(card_translation)
    if  verify_card_number(translated_card_number):
        print('VALID!')
    else:
        print('INVALID!')

# User Editable Region


main()

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Challenge Information:

Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 33

2

Hi there and welcome to our community!

You have an extra space after if here, which is causing the code to fail:

The function verify_card_number returns a Boolean (i.e. it will return a value of either true or false). So your if statement will evaluate the expression verify_card_number(translated_card_number) and if it returns true, it will execute the code inside the if block. If it returns false, it will execute the code in the else block.