On Sun, Apr 03, 2022 at 07:24:42PM -0000, Brian McCall wrote:
> Let's say we have one of your class-ical ( :D ) geometrical shapes
> hierarchy, including an abstract Shape class.
>
> ```
> class Shape(abc.ABC):
> @abc.abstractmethod
> def area(self):
> """"""
The rest of your code sample only shows single inheritence, so it is
doubtful that the issues you had were related to the issues in this
thread.
> In my mind, the best way to make the code work, and promote use and
> contribution to it, is to make it so that users can pass in callables
> instead of fixed values to __init__, and the machinery that returns an
> object will create properties to represent that value if it is a
> callable, otherwise attributes as shown above.
That sounds like a convoluted solution, but maybe I don't understand
your requirements.
> I will not detail my
> solution here, but if you know how properties work, then you know that
> this solution requires classes to be generated on the fly.
I thought I understood how properties work, but I didn't know (and still
don't) that this solution requires classes to be generated on the fly.
Does that imply that every shape instance has its own unique class?
> This problem was a tough nut to crack
Perhaps I don't understand your requirements, but this sounds like a
trivial nut to crack. Put the logic in your properties:
@property
def radius(self):
r = self._radius
if callable(r):
return r()
else:
return r
Although I'm not sure why you want the radius of a shape to be a
callable in the first place. Seems all very over-engineered.
Anyway, there's nothing in your description here that hints as to how or
why super() is an issue, except in the sense that you're doing
Complicated Things™ with metaclasses, `__new__`, dynamically-generated
classes, ABCs, properties, and very possibly the Philosopher's Stone
*wink*, so I'm not surprised you ran into difficulties.
By the way, what super does is explained in fine detail here:
https://www.python.org/download/releases/2.3/mro/
I know, I know, who goes looking through the docs for Python 2.3 for
current features??? But you get to that link via the glossary entry for
"method resolution order".
--
Steve
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