vigenere_cipher.py

init_phrase = "Hi! I'm a Software Developer"
custom_key = 'qwertyuiopasdfghjklzxcvbnm'

def vigenere(message, key):
    key_index = 0
    alphabet = 'abcdefghijklmnopqrstuvwxyz'
    encrypted_text = ''

    for char in message.lower():
    
        # Append space to the message
        if char == ' ':
            encrypted_text += char
        else:        
            # Find the right key character to encode
            key_char = key[key_index % len(key)]
            key_index += 1

            # Define the offset and the encrypted letter
            offset = alphabet.index(key_char)
            index = alphabet.find(char)
            new_index = (index + offset) % len(alphabet)
            encrypted_text += alphabet[new_index]
    
    return encrypted_text

encryption = vigenere(init_phrase, custom_key)
print(encryption)