All,
" And Python can't do that, and that's probably a good thing."
Johnathan, you are right, I emailed this list a year or so ago with a way
to overload assignment and lookup (i.e. what happens when you >>> a) and it
was discussed for a while, but ultimately there were reasons (that I
largely agree with) why that would be problematic in python. The title was
"A proposal (and implementation) to add assignment and LOAD overloading"
for anyone wanting to read the reasoning.
On Wed, Aug 5, 2020 at 2:13 PM Jonathan Goble <jcgob...@gmail.com> wrote:
> On Wed, Aug 5, 2020 at 2:03 PM Ricky Teachey <ri...@teachey.org> wrote:
>
>>
>> And btw this works:
>>
>> >>> class const(int):
>> ... def __new__(cls, name, val):
>> ... obj = super().__new__(cls, val)
>> ... obj.name = name
>> ... return obj
>> ... def about(self):
>> ... print(self.name, '=', self)
>> ...
>> >>> a = const('a', 5)
>> >>> a
>> 5
>> >>> a.about()
>> a = 5
>>
>
> That's literally useless, because after running that there is nothing
> stopping you from doing:
>
> >>> a = 10
>
> or even:
>
> >>> a = "python has no constants"
>
> And now a has a value different from 5.
>
> There is nothing even remotely resembling const-ness to that class. In
> order to get const-ness, you would need the ability to overload
> assignments, like C++ can do. And Python can't do that, and that's probably
> a good thing.
> _______________________________________________
> Python-ideas mailing list -- python-ideas@python.org
> To unsubscribe send an email to python-ideas-le...@python.org
> https://mail.python.org/mailman3/lists/python-ideas.python.org/
> Message archived at
> https://mail.python.org/archives/list/python-ideas@python.org/message/TCW3TAPS6WTHGENNL2G2M5DTCKQWRJE6/
> Code of Conduct: http://python.org/psf/codeofconduct/
>
--
Nate Lust, PhD.
Astrophysics Dept.
Princeton University
_______________________________________________
Python-ideas mailing list -- python-ideas@python.org
To unsubscribe send an email to python-ideas-le...@python.org
https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
https://mail.python.org/archives/list/python-ideas@python.org/message/PGQUKE4HF3IE4DGYVF7PQGTDTGXFNLWP/
Code of Conduct: http://python.org/psf/codeofconduct/
