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Groups > comp.lang.python > #63969
| Date | 2014-01-15 05:03 -0600 |
|---|---|
| From | Tim Chase <python.list@tim.thechases.com> |
| Subject | Re: Chanelling Guido - dict subclasses |
| References | <52d5e408$0$29970$c3e8da3$5496439d@news.astraweb.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.5499.1389783753.18130.python-list@python.org> (permalink) |
On 2014-01-15 01:27, Steven D'Aprano wrote: > class TextOnlyDict(dict): > def __setitem__(self, key, value): > if not isinstance(key, str): > raise TypeError > super().__setitem__(key, value) > # need to override more methods too > > > But reading Guido, I think he's saying that wouldn't be a good > idea. I don't get it -- it's not a violation of the Liskov > Substitution Principle, because it's more restrictive, not less. > What am I missing? Just as an observation, this seems almost exactly what anydbm does, behaving like a dict (whether it inherits from dict, or just duck-types like a dict), but with the limitation that keys/values need to be strings. -tkc
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Chanelling Guido - dict subclasses Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-15 01:27 +0000
Re: Chanelling Guido - dict subclasses Ned Batchelder <ned@nedbatchelder.com> - 2014-01-14 21:04 -0500
Re: Chanelling Guido - dict subclasses Terry Reedy <tjreedy@udel.edu> - 2014-01-14 22:48 -0500
Re: Chanelling Guido - dict subclasses F <f@hop2it.be> - 2014-01-15 07:00 +0000
Re: Chanelling Guido - dict subclasses Peter Otten <__peter__@web.de> - 2014-01-15 09:40 +0100
Re: Chanelling Guido - dict subclasses John Ladasky <john_ladasky@sbcglobal.net> - 2014-01-15 08:51 -0800
Re: Chanelling Guido - dict subclasses Peter Otten <__peter__@web.de> - 2014-01-15 19:35 +0100
Re: Chanelling Guido - dict subclasses Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-01-15 22:30 -0800
Re: Chanelling Guido - dict subclasses Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-15 09:10 +0000
Re: Chanelling Guido - dict subclasses Tim Chase <python.list@tim.thechases.com> - 2014-01-15 05:03 -0600
Re: Chanelling Guido - dict subclasses Daniel da Silva <var.mail.daniel@gmail.com> - 2014-01-15 19:50 -0500
Re: Chanelling Guido - dict subclasses Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-01-16 17:17 +1300
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