Vigenère Cipher

This Python script implements the Vigenère cipher, a method of encryption that uses a repeating keyword to obscure plaintext. This implementation supports both uppercase and lowercase letters, as well as special characters.

Functions:

vigenere(query, key, decrypt=False): Encrypts or decrypts a given text using the Vigenère cipher.

query: The input text to be encrypted or decrypted. key: The keyword used for encryption. decrypt: A boolean flag indicating whether to decrypt (True) or encrypt (False).

Sample Usage:

encrypted_text = vigenere("Hello, World!", "secret")
print(encrypted_text)  # Output: Rotq, Ebiqv!

decrypted_text = vigenere(encrypted_text, "secret", decrypt=True)
print(decrypted_text)  # Output: Hello, World!