• getCharacterBackward(char, key) - return left-shifted character.

This function is performing the opposite behavior of the previous function. After being called, it gets the character to the left of char by moving backward by the specified key positions in the alphabet. For example, if you this function with the parameter c and 2 the result is a and if you call it with a and len(createAlphabet()) the result is a because you are essentially moving over all the characters and so the result is the initial character.

def getCharacterBackward(char, key): """ Given a character char, and an integer key, the function shifts char backward `key` steps. Return the new character. If `char` is not a single character, return `None`. If `key` is not an integer, return -1. """ return "stub"

alphabet reverse A B C D E F G H I J K L M ZY X W VU TSRQPON NOPQRSTU V W X Y Z MLKJI HGFED CBA Plaintext: CAT Ciphertext: XZG wikiHow to Create Substitution Ciphers