[Python-Dev] About [].append == [].append

[Ivan Pozdeev]

On 22.06.2018 19:41, Steven D'Aprano wrote:
> On Fri, Jun 22, 2018 at 08:13:44AM -0700, Guido van Rossum wrote:
>
>> Honestly it looks to me like the status quo is perfect.
> Does this example work for you?
>
> py> (17.1).hex == (17.1).hex
> True
>
> But:
>
> py> a = 17.1
> py> b = 17.1
> py> a.hex == b.hex
> False
>
> I know why it happens -- at the REPL, the interpreter uses the same
> object for both 17.1 instances when they're part of the same statement,
> but not when they're on separate lines. I just don't know whether this
> is desirable or not.
>
>
Strictly speaking, I can't see anything in the docs about method 
equality semantics.
If that's true, it's an implementation detail, and users shouldn't rely 
on it.
Consequently, anything is "desirable" that is sufficient for the Python 
codebase.

-- 
Regards,
Ivan