有时候在使用某个python func的时候，我们需要告诉用户，这个函数马上就要被废弃了，不能使用了，我们可以通过修饰的办法做到：

import cv2 as cv
import numpy as np
import os
import functools
import warnings

class AVDeprecationWarning(DeprecationWarning):
    pass


class AttributeRenamedWarning(AVDeprecationWarning):
    pass

class MethodDeprecationWarning(AVDeprecationWarning):
    pass

class method(object):
    def __init__(self, func):
        functools.update_wrapper(self, func, ("__name__", "__doc__"))
        self.func = func

    def __get__(self, instance, cls):
        warning = MethodDeprecationWarning(
            "{}.{} is deprecated.".format(cls.__name__, self.func.__name__)
        )
        warnings.warn(warning, stacklevel=2)
        return self.func.__get__(instance, cls)

class Buffer(object):
    @method
    def buffer_size(self):
        return 0
    

b=Buffer()
c=b.buffer_size()
print(c)

        

当用户使用buffer_size()的时候就会打印提示信息：

test.py:36: MethodDeprecationWarning: Buffer.buffer_size is deprecated.
  c=b.buffer_size()
0