How to detect method overloading in subclasses in python?

You can use your own decorator. But this is a trick and will only work on classes where you control the implementation.

def override(method):  method.is_overridden = True  return methodclass Super:   def __init__(self):      if hasattr(self.method, 'is_overridden'):         print 'different'      else:         print 'same'   @classmethod   def method(cls):      passclass Sub1(Super):   @override   def method(self):      print 'hi'class Sub2(Super):   passSuper() # should be sameSub1() # should be differentSub2() # should be same>>> same>>> different>>> same

It seems simplest and sufficient to do this by comparing the common subset of the dictionaries of an instance and the base class itself, e.g.:

def detect_overridden(cls, obj):  common = cls.__dict__.keys() & obj.__class__.__dict__.keys()  diff = [m for m in common if cls.__dict__[m] != obj.__class__.__dict__[m]]  print(diff)def f1(self):  passclass Foo:  def __init__(self):    detect_overridden(Foo, self)  def method1(self):    print("Hello foo")  method2=f1class Bar(Foo):  def method1(self):    print("Hello bar")  method2=f1 # This is pointless but not an override#  def method2(self):#    passb=Bar()f=Foo()

Runs and gives:

['method1'][]

In reply to answer https://stackoverflow.com/a/9437273/1258307, since I don't have enough credits yet to comment on it, it will not work under python 3 unless you replace im_func with __func__ and will also not work in python 3.4(and most likely onward) since functions no longer have the __func__ attribute, only bound methods.

EDIT: Here's the solution to the original question(which worked on 2.7 and 3.4, and I assume all other version in between):

    class Super:        def __init__(self):            if self.method.__code__ is Super.method.__code__:                print('same')            else:                print('different')        @classmethod        def method(cls):            pass    class Sub1(Super):        def method(self):            print('hi')    class Sub2(Super):        pass    Super() # should be same    Sub1() # should be different    Sub2() # should be same

And here's the output:

samedifferentsame