On Saturday, March 17, 2012 6:04:58 PM UTC+8, Cosmia Luna wrote:
> On Saturday, March 17, 2012 5:25:06 PM UTC+8, Peter Otten wrote:
> > Cosmia Luna wrote:
> >
> > > I'm porting my existing work to Python 3.X, but...
> > >
> > > class Foo:
> > > def bar(self):
> > > pass
> > >
> > > mthd = Foo.bar
> > >
> > > assert mthd.im_class is Foo # this does not work in py3k
> > >
> > > So, how can I get a reference to Foo? This is important when writing
> > > decorators, the only way I can think out is:
> > >
> > > class Foo:
> > > def bar(self):
> > > 'Foo' # manually declare the owner class
> > > pass
> > >
> > > mthd = Foo.bar
> > >
> > > assert mthd.__globals__[mthd.__doc__] is Foo # this works
> > >
> > > class Child(Foo):
> > > def bar(self):
> > > 'Child' # I have to override all method defined by bar but do
> > > nothing pass
> > >
> > > child_mthd = Child.bar
> > >
> > > assert child_mthd.__globals__[child_mthd.__doc__] is Child # this works
> > >
> > > But the code above is quite ugly and abuses the __doc__. Is there any
> > > equivalent in py3k of im_class?
> >
> > class set_class:
> > def __init__(self, method):
> > self.method = method
> > def __get__(self, instance, class_):
> > if instance is None:
> > method = self.method
> > def f(*args, **kw):
> > return method(*args, **kw)
> > f.im_class = class_
> > f.__name__ = method.__name__
> > return f
> > return self.method.__get__(instance, class_)
> >
> > class Foo:
> > def __init__(self, name):
> > self.name = name
> > @set_class
> > def bar(self):
> > print("%s says hello from bar()" % self)
> > def __str__(self):
> > return self.name
> >
> > class Bar(Foo):
> > pass
> >
> > assert Foo.bar.im_class is Foo
> > assert Bar.bar.im_class is Bar
> >
> > Foo("Fred").bar()
> > Foo.bar(Foo("Fred"))
> >
> > Bar("Fred").bar()
> > Bar.bar(Bar("Fred"))
> >
> > The cleaner approach is probably:
> >
> > Rule('/<action>/', endpoint=(RootController, RootController.otheraction))
> > ...
> > Controller, method = endpoint
> > controller = Controller(Request(environ))
> > ...
> > method(controller)
>
>
> That's exactly what I want, and I think you're right, the approach below is
> cleaner.
> Rule('/<action>/', endpoint=(RootController, RootController.otheraction)).
>
> Thanks a lot.
> Cosmia
Oh I'm wrong.
If I use a decorator, the decorator will NEVER get the owner class even in
Python 2.X. The function is just plain function instead of unbound method
before the code of a class is fully evaluated. So the decorator ALWAYS receives
a plain function.
I'll look into the module inspect and try to get the frame of calling...
Cosmia
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