curriculum/challenges/english/blocks/learn-string-manipulation-by-building-a-cipher/65553159615a8123b190ee43.md
It works! Now, you are going to start with an encrypted message to be decrypted.
Change the value of text to the string 'mrttaqrhknsw ih puggrur'.
You should still have a text variable.
({ test: () => assert(__userGlobals.has("text")) })
Your text variable should have the value of 'mrttaqrhknsw ih puggrur'.
({ test: () => assert.equal(__userGlobals.get("text"), "mrttaqrhknsw ih puggrur") })
--fcc-editable-region--
text = 'Hello Zaira!'
custom_key = 'python'
--fcc-editable-region--
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)
encryption = encrypt(text, custom_key)
print(encryption)
decryption = decrypt(encryption, custom_key)
print(decryption)