Debug an ISBN Validator - Debug an ISBN Validator

Python
1

Tell us what’s happening:

I am confused on lines 64 and 67. I am confused because if i convert the string form the input into a integer steps 7 and 8, which confirm whether the isbn and value is a integer, return incorrect but my code now says it is correct.

I would like to know if there is a better way to check for it being an integer.

Also another problem is that i can never get my isbn to validate as correct.

Thanks for the help and tips.

Your code so far

def validate_isbn(isbn, length):
    isbn = str(isbn)
    if len(isbn) != length:
        print(f'ISBN-{length} code should be {length} digits long.')
        return
    main_digits = isbn[0:length + 1]
    print(main_digits)
    given_check_digit = isbn[length-1]
    main_digits_list = [int(digit) for digit in main_digits]
    # Calculate the check digit from other digits
    if length == 10:
        expected_check_digit = calculate_check_digit_10(main_digits_list)
    else:
        expected_check_digit = calculate_check_digit_13(main_digits_list)
    # Check if the given check digit matches with the calculated check digit
    if given_check_digit == expected_check_digit:
        print('Valid ISBN Code.')
    else:
        print('Invalid ISBN Code.')
def calculate_check_digit_10(main_digits_list):
    # Note: You don't have to fully understand the logic in this function.
    digits_sum = 0
    # Multiply each of the first 9 digits by its corresponding weight (10 to 2) and sum up the results
    for index, digit in enumerate(main_digits_list):
        digits_sum += digit * (10 - index)
    # Find the remainder of dividing the sum by 11, then subtract it from 11
    result = 11 - digits_sum % 11
    # The calculation result can range from 1 to 11.
    # If the result is 11, use 0.
    # If the result is 10, use upper case X.
    # Use the value as it is for other numbers.
    if result == 11:
        expected_check_digit = '0'
    elif result == 10:
        expected_check_digit = 'X'
    else:
        expected_check_digit = str(result)
    return expected_check_digit
def calculate_check_digit_13(main_digits_list):
    # Note: You don't have to fully understand the logic in this function.
    digits_sum = 0
    # Multiply each of the first 12 digits by 1 and 3 alternately (starting with 1), and sum up the results
    for index, digit in enumerate(main_digits_list):
        if index % 2 == 0:
            digits_sum += digit * 1
        else:
            digits_sum += digit * 3
    # Find the remainder of dividing the sum by 10, then subtract it from 10
    result = 10 - digits_sum % 10
    # The calculation result can range from 1 to 10.
    # If the result is 10, use 0.
    # Use the value as it is for other numbers.
    if result == 10:
        expected_check_digit = '0'
    else:
        expected_check_digit = str(result)
    return expected_check_digit
def main():
    user_input = input('Enter ISBN and length: ')
    try:
        if ',' not in user_input:
            print('Enter comma-separated values.')
        values = user_input.split(',')
        isbn = values[0]
        if not isinstance(isbn, int):
            print('Invalid character was found.')
        length = int(values[1])
        if not isinstance(length, int):
            print('Length must be a number.')
        if length == 10 or length == 13:
            validate_isbn(isbn, length)
        else:
            print('Length should be 10 or 13.')
    except ValueError:
        print('Length must be a number.')
# main()

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Challenge Information:

Debug an ISBN Validator - Debug an ISBN Validator

2

Hi,
your “validate_isbn(isbn, length)” function is called in 71 line,
then all above (line 64-67 ) did not know about your check .