我需要写一个程序，生成所有可能的大写和小写组合的单词密码

def generate_passwords(word, index, password):
    if index == len(word):
        print(password)
        return

    if word[index].isalpha():
        generate_passwords(word, index + 1, password + word[index].lower())
        generate_passwords(word, index + 1, password + word[index].upper())
    else:
        generate_passwords(word, index + 1, password + word[index])

word = "password"
generate_passwords(word, 0, "")

password
passworD
passwor
passwoRd
passwoRD
passwoR
...