curriculum/challenges/english/blocks/learn-string-manipulation-by-building-a-cipher/6555e5991af57d1ae0e35f0a.md
Wait a minute! You cannot decrypt anything with the wrong key. Try with 'happycoding'.
With that, your cipher project is complete.
You should still have a custom_key variable.
({ test: () => assert(__userGlobals.has("custom_key")) })
You should modify the custom_key value into 'happycoding'.
({ test: () => assert.equal(__userGlobals.get("custom_key"), "happycoding") })
--fcc-editable-region--
text = 'mrttaqrhknsw ih puggrur'
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')
--fcc-editable-region--
text = 'mrttaqrhknsw ih puggrur'
custom_key = 'happycoding'
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')