How to get/set class attributes in Python

[George Sakkis]

"alex23" wrote:

> Kalle Anke wrote:
> > I'm coming to Python from other programming languages. I like to
> > hide all attributes of a class and to only provide access to them
> > via methods.
>
> I'm pretty fond of this format for setting up class properties:
>
>     class Klass(object):
> def propname():
>     def fget: pass
>     def fset: pass
>     def fdel: pass
>     def doc: """pass"""
>     return locals()
> propname = property(**propname())
>
> (Replacing 'pass' in the getters & setters et.al with the actual
> functionality you want, of course...)
>
> This method minimises the leftover bindings, effectively leaving the
> getter/setter methods bound only to the property, ensuring they're only
> called when the property is acted upon.
>
> Incidentally, kudos & thanks to whomever I originally stole it from :)
>
> -alex23

And a slight improvement in readability IMHO (for python 2.4+) is the
following recipe:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/410698.
Using the Property decorator, the property declaration above becomes:

class Klass(object):
    @Property         # <--- the capitalized 'P' is not a typo
    def propname():
        '''Documentation'''
        def fget: pass
        def fset: pass
        def fdel: pass

The Property decorator peeks automagically the fget, fset, fdel and
__doc__ from the property's locals(), instead of having the property
return locals() explicitly. Also, it doesn't break when the property
defines local variables other than [fget, fset, fdel, doc]. 

George