Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 19

Python
1

Use a for loop to iterate over each digit in the odd_digits list. Move your print call from the previous step into the for loop, and change it to print each digit.

Your code so far


# User Editable Region

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

for digits in odd_digits:
    odd_digits = card_number_reversed[::2]
    print(odd_digits)
    

# User Editable Region

def main():
    card_number = '4111-1111-4555-1142'
    card_translation = str.maketrans({'-': '', ' ': ''})
    translated_card_number = card_number.translate(card_translation)

    verify_card_number(translated_card_number)

main()

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Challenge Information:

Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 19

2

you can’t use odd_digits in the loop if you create it inside the loop: move the declaration of odd_digits to before the loop

then change the loop variable to digit without the S

and then print each digit in the loop with print

1 Like
3

No need for “odd and S”…
Remove and try again

4

I’ve done the same keeping the odd_digits definition before the loop, but the console report that odd_digits is not defined.

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:
    print(odd_digits)
5

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