普通装饰器

from functools import wraps

def cover(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        result = func(*args, **kwargs)
        return result
    return wrapper

类内部装饰器，可调用类内部函数

from functools import wraps

class T(object):
    def __init__(self):
        pass

    def cover(func):
        """读取最新的数据到内存，写数据到硬盘"""
        @wraps(func)
        def wrapper(self, *args, **kwargs):
            do_something()
            result = func(self, *args, **kwargs)
            do_else()
            return result
        return wrapper

    @cover
    def get_schema(self, arg1, arg2):
        work...