crack the code.py

# Define a function to find the truth by shifting the letter by a specified amount
def lasso_letter(letter, shift_amount):
    # Invoke the ord function to translate the letter to its ASCII code
    # Save the code value to the variable called letter_code
    letter_code = ord(letter.lower())

    # The ASCII number representation of lowercase letter a
    a_ascii = ord('a')

    # The number of letters in the alphabet
    alphabet_size = 26

    # The formula to calculate the ASCII number for the decoded letter
    # Take into account looping around the alphabet
    true_letter_code = a_ascii + (((letter_code - a_ascii) + shift_amount) % alphabet_size)

    # Convert the ASCII number to the character or letter
    decoded_letter = chr(true_letter_code)

    # Send the decoded letter back
    return decoded_letter


# Define a function to find the truth in a secret message
# Shift the letters in a word by a specified amount to discover the hidden word
def lasso_word(word, shift_amount):
    # This variable is updated each time another letter is decoded
    decoded_word = ""

    # This for loop iterates through each letter in the word parameter
    for letter in word:
        # The lasso_letter() function is invoked with each letter and the shift amount
        # The result (the decoded letter) is stored in a variable called decoded_letter
        decoded_letter = lasso_letter(letter, shift_amount)

        # The decoded_letter value is added to the end of the decoded_word value
        decoded_word = decoded_word + decoded_letter

    # The decoded_word is sent back to the line of code that invoked this function
    return decoded_word


# Try to decode the word "terra"
print( "Shifting Ncevy by 13 gives: \n" + lasso_word( "Ncevy", 13 ) )
print( "Shifting gpvsui by 25 gives: \n" + lasso_word( "gpvsui", 25 ) )
print( "Shifting ugflgkg by -18 gives: \n" + lasso_word( "ugflgkg", -18 ) )
print( "Shifting wjmmf by -1 gives: \n" + lasso_word( "wjmmf", -1 ) )