Re: On properties, use object instead?

On Thu, 8 Jul 2004 09:10:15 +0100 (BST) Mukhsein Johari <[email protected]> wrote:

> Mark,
> I'm not sure if objects have set_, get_ methods but if
> they did, we would not need prop keyword to implement
> properties.
> 
> Simply (using the example in the tutorial wiki):
> 
> O>> object Widget:
> ...    price = 76
> ...    tax   = 2.12
> ...
> 2.12
> O>> w = Widget()
> <Object:c08db8>
> O>> w.tax
> 2.12
> O>> with Widget:
> ...    object tax:        # change tax to a 'property'
> ...       def get_():     # define get_ method
> ...          return self.price * 0.03
> ...
> O>> w.tax
> 2.28
> O>> Widget.price = 82
> 82
> O>> w.tax
> 2.46
> O>> w.tax = 3
> 
> Uncaught exception:
> --- File: wtax3-src.txt, line: 1, char: 3
> Type Error, write attempt on an object with no set_
> method.
> 
> O>>
> 
The object level get_, set_ and del_ are for overriding all attribute lookup
on an object like Python's __getattribute__, __setattr__ and __delattr__.
They are part of a wild-card property that acts on any attribute.

Lenard Lindstrom
<[email protected]>