Caesar Chiper Bruteforce python

key = 'abcdefghijklmnopqrstuvwxyz'

def encrypt(n, plaintext):
    """Encrypt the string and return the ciphertext"""
    result = ''

    for l in plaintext.lower():
        try:
            i = (key.index(l) + n) % 26
            result += key[i]
        except ValueError:
            result += l

    return result.lower()


def decrypt(n, ciphertext):
    """Decrypt the string and return the plaintext"""
    result = ''

    for l in ciphertext:
        try:
            i = (key.index(l) - n) % 26
            result += key[i]
        except ValueError:
            result += l

    return result

for i in range(27): 
    print i, decrypt (i,"frynzng. naqn oryhz orehaghat ")
    print encrypt(3,"wiki")

credit by kak thomas thanks..