python字典查询功能

def fetch(data):
    print(' 查询功能')
    print('用户数据是',data)
 
def add():
    pass
 
def change():
    pass
 
def delete():
    pass
 
if __name__ == '__main__':
 
    msg = '''
    1: 查询
    2. 添加
    3. 修改
    4. 删除
    5. 退出
    '''
 
    msg_dict = {
        '': fetch,
        '': add,
        '': change,
        '': delete
    }
 
    while True:
        print(msg)
        choice = input('请输入你的选项:').strip()
 
        if not choice:
            continue
        if choice == '':
            break
 
        data = input('请输入你的数据：').strip()
        msg_dict[choice](data)