下面有一个元类，它用来检测重载方法，确保它的调用参数跟父类中原始方法有着相同的参数签名

from inspect import signature
import logging

class MatchSignaturesMeta(type):

def __init__(self, clsname, bases, clsdict):
    super().__init__(clsname, bases, clsdict)
    sup = super(self, self)
    for name, value in clsdict.items():
        if name.startswith('_') or not callable(value):
            continue
        # Get the previous definition (if any) and compare the signatures
        prev_dfn = getattr(sup,name,None)
        if prev_dfn:
            prev_sig = signature(prev_dfn)
            val_sig = signature(value)
            if prev_sig != val_sig:
                logging.warning('Signature mismatch in %s. %s != %s',
                                value.__qualname__, prev_sig, val_sig)

Example

class Root(metaclass=MatchSignaturesMeta):
pass

class A(Root):
def foo(self, x, y):
pass

def spam(self, x, *, z):
    pass

Class with redefined methods, but slightly different signatures

class B(A):
def foo(self, a, b):
pass

def spam(self,x,z):
    pass

运行结果

WARNING:root:Signature mismatch in B.spam. (self, x, *, z) != (self, x, z)
WARNING:root:Signature mismatch in B.foo. (self, x, y) != (self, a, b)