def validate_credit_card(number):
    """Validate a credit card number using the Luhn algorithm without list comprehensions."""
    digits = str(number)[::-1]  # Reverse the credit card number as a string
    doubled_digits = []
    total_sum = 0

    for i, digit in enumerate(digits):
        digit = int(digit)
        if i % 2 == 1:  # Double every second digit
            doubled_digit = digit * 2
            if doubled_digit > 9:  # Subtract 9 if the result is greater than 9
                doubled_digit -= 9
        else:
            doubled_digit = digit

        doubled_digits.append(doubled_digit)  # Append the processed digit to the list

    total_sum = sum(doubled_digits)  # Sum all the digits

    return total_sum % 10 == 0  # If the sum modulo 10 is 0, the card number is valid

# Example usage:
card_number = "4532015112830366"  # This is a randomly generated example number
is_valid = validate_credit_card(card_number)
is_valid