Function main

src/gamesbyexample/railfencecipher.py:13–46

()

def main():
    print('Rail Fence Cipher, by Al Sweigart al@inventwithpython.com')

    # Ask the user if they want to encrypt or decrypt:
    while True:
        print('Do you want to (E)ncrypt or (D)ecrypt?')
        mode = input('> ').upper()
        if mode == 'E' or mode == 'D':
            break

    # Ask the user for the message to encrypt or decrypt:
    while True:
        print('Enter a message up to 75 characters long:')
        print('|' + ('-' * 73) + '|')
        message = input('> ')
        if 0 < len(message) <= 75:
            break

    # Ask the user for the key number.
    while True:
        print('Enter the key number 2 to 12:')
        response = input('> ')
        try:
            key = int(response)
        except:
            print('You must enter a number.')
        if 2 <= key <= 12:
            break

    # Encrypt or decrypt the message:
    if mode == 'E':
        encryptMessage(message, key)
    elif mode == 'D':
        decryptMessage(message, key)


def getBlankRails(message, key):