Re: new minor getAttr feature

On Mon, 12 Jul 2004 21:37:41 -0700 Mark Hahn <[email protected]> wrote:

> http://prothon.org/wiki?pagename=Object.getAttr%28%29
> 
> This will be in the next interim release.
>
In Python the getattr function has matching setattr and delattr
functions for setting and deleting attributes respectively.

The non-super version of getAttr is simply obj.attrs_[name] .

getAttr should through a NameError if the attribute is not found since
None is a valid attribute value.

And I guess getAttr, like attrs_, will be a truly special method,
uneffected by wild-card property methods. I had not noticed it before
but the following does not cause infinite recursion:

O>> object Wild:
...    def get_(attr):
...       print("Getting", attr)
...       return self.attrs_[attr]
...    d = 8
...    e = 9
...
9
O>> Wild.d
Getting $d
8
O>> Wild.e
Getting $e
9

I guess there is no way around these magic attributes since there are no
classes, which bypass the property mechanism. Alternatively, one could have
functions.

getAttr(obj, name)
getAttrs(obj)        # Return object attribute list; replaces attrs_
setAttr(obj, name, value)
delAttr(obj, name)

Nothing magical about these. But I would have these do normal attribute lookup,
which means honouring properties.

To bypass properties I would have special getAttrIgnoreProp, setAttrIgnoreProp
and delAttrIgnoreProp functions. They have verbose names but they are for special
use only.

Lenard Lindstrom
<[email protected]>