凯撒密码加密解密python编程

凯撒密码是一种简单的替换式加密技术，通过将明文中的每个字符按照字母表向右（或向左）固定位数偏移来加密。在Python中实现凯撒密码，你可以创建一个函数来执行加密和解密操作。

**加密示例**:

def caesar_cipher_encrypt(text, shift):
    encrypted_text = ""
    for char in text:
        if char.isalpha():
            # 对英文字符处理大写和小写字母
            shift_amount = shift % 26
            if char.islower():
                new_char = chr((ord(char) - ord('a') + shift_amount) % 26 + ord('a'))
            else:
                new_char = chr((ord(char) - ord('A') + shift_amount) % 26 + ord('A'))
        else:
            new_char = char  # 非字母字符保持不变
        encrypted_text += new_char
    return encrypted_text

# 示例
plaintext = "Hello, World!"
shift = 3
encrypted = caesar_cipher_encrypt(plaintext, shift)
print(f"Encrypted: {encrypted}")

**解密示例**:

def caesar_cipher_decrypt(ciphertext, shift):
    return caesar_cipher_encrypt(ciphertext, -shift)

decrypted = caesar_cipher_decrypt(encrypted, shift)
print(f"Decrypted: {decrypted}")