[Python-porting] Pickling unbound methods on Python 3

["Martin v. Löwis"]

> I know that unbound methods are of the function type in Python 3. I'm
> calling them unbound methods because they are methods of classes which
> are not bound to an instance. I'm aware they have no special stance, but
> I still refer to them as unbound methods.

Neglecting reality doesn't help your cause, though. You'll need to 
understand *why* pickling fails, and then see whether there might be
a solution.

A work-around is to put all methods you want to pickle into module-scope
of your module

class Foo:
   def bar(self):
     pass

bar = Foo.bar

Now you can pickle Foo.bar.

Regards,
Martin