On Wed, Aug 5, 2020 at 3:40 PM Ethan Furman <et...@stoneleaf.us> wrote:
> On 8/5/20 11:11 AM, Jonathan Goble wrote: > > > 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. > > --> from aenum import Constant > > --> class K(Constant): > ... a = 5 > ... b = 'hello' > ... > > --> K.a > <K.a: 5> > > --> K.a == 5 > True > > --> K.a - 3 > 2 > > --> K.a = 9 > Traceback (most recent call last): > ... > AttributeError: cannot rebind constant <K.a> > > --> del K.a > Traceback (most recent call last): > ... > AttributeError: cannot delete constant <K.a> > > However, one can, of course: > > del K > > There is only so much one can do. ;-) > > Actually, it is possible to do with Python, using an import hook. See https://aroberge.github.io/ideas/docs/html/constants.html André Roberge > -- > ~Ethan~ > _______________________________________________ > 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/VUZKCKX7CARMZI3BNDQRGA7U4HHDXDMP/ > Code of Conduct: http://python.org/psf/codeofconduct/ >
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