I build a cipher text = 'code with umer' custom_key = 'python'
def vigenere(message, key, direction=1): key_index = 0 alphabet = 'abcdefghijklmnopqrstuvwxyz' final_message = ''
for char in message.lower():
# Append any non-letter character to the message
if not char.isalpha():
final_message += char
else:
# Find the right key character to encode/decode
key_char = key[key_index % len(key)]
key_index += 1
# Define the offset and the encrypted/decrypted letter
offset = alphabet.index(key_char)
index = alphabet.find(char)
new_index = (index + offset*direction) % len(alphabet)
final_message += alphabet[new_index]
return final_message
def encrypt(message, key): return vigenere(message, key)
def decrypt(message, key): return vigenere(message, key, -1)
print(f'\nEncrypted text: {text}') print(f'Key: {custom_key}') decryption = decrypt(text, custom_key) print(f'\nDecrypted text: {decryption}\n')