Re: Immutability and Python

References	<CAF_E5Jbf0KJjDLV0jS-p_J9E4D8=_sPScgE+vkmkN2sMw=3aoA@mail.gmail.com> <1793477354.3492917.1351526431192.JavaMail.root@sequans.com>
Date	2012-10-29 16:12 +0000
Subject	Re: Immutability and Python
From	andrea crotti <andrea.crotti.0@gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.3025.1351527152.27098.python-list@python.org> (permalink)

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2012/10/29 Jean-Michel Pichavant <jeanmichel@sequans.com>:
>
>
> In an OOP language num.increment() is expected to modify the object in place.
> So I think you're right when you say that functional languages technics do not necessarily apply to Python, because they don't.
>
> I would add that what you're trying to suggest in the first post was not really about immutability, immutable objects in python are ... well immutable, they can be used as a dict key for instance, your NumWrapper object cannot.
>
>
> JM

Yes right immutable was not the right word, I meant that as a contract
with myself I'm never going to modify its state.

Also because how doi I make an immutable object in pure Python?

But the example with the dictionary is not correct though, because this:

In [145]: class C(object):
   .....:     def __hash__(self):
   .....:         return 42
   .....:

In [146]: d = {C(): 1}

works perfectly, but an object of class C can mutate as much as it
wants, as my NumWrapper instance..

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Thread

Re: Immutability and Python andrea crotti <andrea.crotti.0@gmail.com> - 2012-10-29 16:12 +0000
  Re: Immutability and Python Paul Rubin <no.email@nospam.invalid> - 2012-10-29 09:46 -0700
    Re: Immutability and Python andrea crotti <andrea.crotti.0@gmail.com> - 2012-10-29 17:05 +0000
      Re: Immutability and Python Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-10-29 22:30 +0000
        Re: Immutability and Python Chris Kaynor <ckaynor@zindagigames.com> - 2012-10-29 15:45 -0700
          Re: Immutability and Python Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-10-29 23:14 +0000
    Re: Re: Immutability and Python Evan Driscoll <driscoll@cs.wisc.edu> - 2012-10-29 12:58 -0500
    Re: Immutability and Python Terry Reedy <tjreedy@udel.edu> - 2012-10-29 14:03 -0400
    Re: Immutability and Python Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-10-29 14:25 -0400

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