copy_method.py

# -*- coding: utf-8 -*-

from types import FunctionType

def copy_func(f, name=None):
  return FunctionType(f.func_code, f.func_globals, name or f.func_name, f.func_defaults, f.func_closure)

class Foo(object):
  def method(self, arg):
    self.value = arg
    return self.value


class Bar(object):
  def get_value(self):
    return self.value


if __name__ == "__main__":
  foo = Foo()
  bar = Bar()

  method = copy_func(Foo.method)
  Bar.method = method

  assert foo.method is not bar.method and bar.method is not method, "Method was not copied correctly"