我正在试着做一个搜索程序，但不知道如何打印用户名和全名

class User:
    def __init__(self, username, full_name):
        self.username = username
        self.full_name = full_name

# 假设有一组用户数据
users = [
    User("user1", "John Doe"),
    User("user2", "Jane Smith"),
    User("user3", "Alice Johnson")
]

def search_users(keyword):
    matched_users = []
    for user in users:
        if keyword.lower() in user.username.lower() or keyword.lower() in user.full_name.lower():
            matched_users.append(user)
    return matched_users

def print_user_info(users):
    for user in users:
        print("Username: ", user.username)
        print("Full Name: ", user.full_name)
        print()

# 示例搜索关键字为 "John"
keyword = "John"
matched_users = search_users(keyword)
print_user_info(matched_users)