introspection - How to check in Python from which class methods is derived? -

i have 2 classes:

class a(object):   def a(self):     pass  class b(a):   def b(self):     pass  print dir(a) print dir(b) 

how can check class methods derived in python?

for example:

getmethodclass(a.a) == getmethodclass(b.a) == getmethodclass(b.b) == b 

interesting question. here how i'd go it.

(this works in python2. haven't tested in python3, won't surprised if not work...)

you can iterate on "nominees" using reversed(inspect.getmro(cls)), , returning first (by fetching next value of iterator) satisfy condition has relevant attr, , attr same method of relevant cls.

method identity-comparison done comparing im_func attribute of unbound method.

import inspect  def getmethodclass(cls, attr):    return next(       basecls basecls in reversed(inspect.getmro(cls))       if hasattr(basecls, attr)       , getattr(basecls, attr).im_func getattr(cls, attr).im_func    )  getmethodclass(a, 'a') => __main__.a getmethodclass(b, 'a') => __main__.a getmethodclass(b, 'b') => __main__.b  # alternative implementation, suggested @chameleon def getattributeclass(cls, attrname):   # check first if has attribute   attr = getattr(cls, attrname)    mro = inspect.getmro(cls)   # 1 class on list   if len(mro) == 1:     return cls    # many class on list   base in reversed(mro[1:]):     # check if defined in base     try:       baseattr = getattr(base, attrname)     except attributeerror:       continue     else:       if baseattr.im_func attr.im_func:         return base   # define in top class   return cls 

the function can have signature suggest:

def getmethodclass(unbound_method):     cls = unbound_method.im_class     attr = unbound_method.__name__     # rest of implementation same before...  getmethodclass(b.a) => __main__.a