[Python-Dev] Duck-typing self

[Sebastian Rittau]

Hi!

I am curious why the following will not work in Python:

  class foo(object):
      def bar(self):
          print self.attr
          
  class duck(object):
      attr = 3.14
  
  foo.bar(duck())

Is it a design decision that duck-typing self does not work or is there a
technical reason? From a practical standpoint it seems that being able to
duck-type self has merit, for example in unit testing complex classes.

 - Sebastian