[Python-ideas] Decorators for variables

[Ian Kelly]

On Fri, Apr 1, 2016 at 11:14 AM, Matthias welp <boekewurm at gmail.com> wrote:
>> An example of the transformation would help here
>
> An example, that detects cycles in a graph, and doesn't do an update if
> the graph has cycles.

Thanks.

> class A(object):
>     def __init__(self, parent):
>         @prevent_cycles
>         self.parent = parent

I think you'll find that this doesn't work. Properties are members of
the class, not of instances of the class.

> This would prevent cycles from being created in this object A, and would
> make
> some highly reusable code. The same can be done for @not_none, etc, to
> prevent
> some states which may be unwanted.

But you could accomplish the same thing with "self.parent =
prevent_cycles(parent)". So I'm still not seeing how the use of the
decorator syntax eliminates repetition.