@Guido
> One would have to introduce some kind of convention
> where you can write properties with a leading _

One doesn't even need the @property decorator in this case.

For example:

def __getattr__(name):

g = globals()

name = '_' + name

if name in g:

return g[name]()

raise AttributeError(...)

def _attr():

"do something"

return actual_object

One can even write a decorator that would change the name automatically

(but this will require a call at the end of module to unbind original names).

The space for play is infinite. The question is what exactly is needed.

I would say that already basic customisation (like __getattr__) will be enough.

IIUC, this will be actually a bit faster than setting __class__ since only "customized"

attributes will be affected.

Ivan