Groups > comp.lang.python > #197794

Re: Python hash return value - what use is it?

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From	Lawrence D’Oliveiro <ldo@nz.invalid>
Newsgroups	comp.lang.python
Subject	Re: Python __hash__ return value - what use is it?
Date	Sun, 31 May 2026 09:25:32 -0000 (UTC)
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On Sun, 31 May 2026 08:28:46 -0000 (UTC), Veek M wrote:

> However when I print the set I see individual instances though I
> want the instances to be the treated the same .ie there should be
> just one instance in the set because the return value from __hash__
> is always 1.
>
> In the dictionary when I print it I see the instances as individual
> keys though I want to see a single key - what gives??

Just tried your code in a Jupyter notebook under Python 3.13.12, and
this was the output:

    in __bool__
    true
    -----
    in __hash__
    in __hash__
    in __eq__ <__main__.MyClass object at 0x7f68a86a4410>
    {<__main__.MyClass object at 0x7f68a8691400>}
    -----
    in __hash__
    in __hash__
    in __eq__ <__main__.MyClass object at 0x7f68a86a4410>
    {<__main__.MyClass object at 0x7f68a8691400>: '20'}

As you expected, only a single element in the set, and only a single
entry in the dict.

Thread

Python __hash__ return value - what use is it? Veek M <veekjunk@foobar.com> - 2026-05-31 08:28 +0000
  Re: Python __hash__ return value - what use is it? Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-05-31 09:25 +0000
    Re: Python __hash__ return value - what use is it? Veek M <veekjunk@foobar.com> - 2026-05-31 10:13 +0000
  Re: Python __hash__ return value - what use is it? ram@zedat.fu-berlin.de (Stefan Ram) - 2026-05-31 09:40 +0000
  Re: Python __hash__ return value - what use is it? Jon Ribbens <jon+usenet@unequivocal.eu> - 2026-05-31 13:06 +0000

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