import functools
# 一次实现带参数和不带参数效果
def log(text=None):
    def decorator(func):
        if text is not None:
            print('%s %s()' % (text, func.__name__))

        @functools.wraps(func)
        def wrapper(*args, **kw):
            print('begin call')
            f = func(*args, **kw)
            print('end call')
            return f

        return wrapper

    return decorator