Python/ciphers/Caesar Cipher.py
2016-08-01 15:06:53 +05:00

44 lines
1.0 KiB
Python

# The Caesar Cipher Algorithm
def main():
message = input("Enter message: ")
key = int(input("Key [1-26]: "))
mode = input("Encrypt or Decrypt [e/d]: ")
if mode.lower().startswith('e'):
mode = "encrypt"
elif mode.lower().startswith('d'):
mode = "decrypt"
LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
translated = ""
message = message.upper()
for symbol in message:
if symbol in LETTERS:
num = LETTERS.find(symbol)
if mode == "encrypt":
num = num + key
elif mode == "decrypt":
num = num - key
if num >= len(LETTERS):
num = num - len(LETTERS)
elif num < 0:
num = num + len(LETTERS)
translated = translated + LETTERS[num]
else:
translated = translated + symbol
if mode == "encrypt":
print("Encryption:", translated)
elif mode == "decrypt":
print("Decryption:", translated)
if __name__ == '__main__':
main()