Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #59172

Re: 'isimmutable' and 'ImmutableNester'

References <CAB6+5b_w+kBT=EDqd9wRO80am+Wp2DgrEqSpVEPWkcTAVmYQtQ@mail.gmail.com> <1384206048.30461.46091021.634F0FCA@webmail.messagingengine.com>
Date 2013-11-12 10:39 +0100
Subject Re: 'isimmutable' and 'ImmutableNester'
From Frank-Rene Schäfer <fschaef@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.2445.1384249197.18130.python-list@python.org> (permalink)

Show all headers | View raw


> All you've done is proven that you can subvert things. By fiddling
> with __hash__, __eq__, and so on, you can make sets and dicts behave
> very oddly. Means nothing.

To the contrary, it means everything about what 'isimmutable' could
contribute: security against advert or inadvert insertion of mutable objects.


2013/11/11  <random832@fastmail.us>:
>> A built-in function 'isimmutable()' shall tell efficiently whether the
>> object
>> of concern is mutable or not.
>
> What's the benefit over attempting to hash() the object?
>
> copy.deepcopy already has special case for int, string, and tuples
> (including tuples that do and do not have mutable members) - could what
> you need be accomplished by overriding __copy__ and __deepcopy__ in your
> custom class to return itself if it is immutable?

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread


Thread

Re: 'isimmutable' and 'ImmutableNester' Frank-Rene Schäfer <fschaef@gmail.com> - 2013-11-12 10:39 +0100

csiph-web