Even though I am just a regular user of Python, +10 for me. It makes sense and
I think I can easily teach it to people. However, (*expr for expr in its)
should be generator expression and should be allowed to have nice mirror to all
the un-packing comprehensions. It would be equivalent to:
def gen(its):
for expr in its:
for x in expr:
yield x
Abdulla
Sent from my iPhone
> On 17 Oct 2021, at 12:28 AM, Guido van Rossum <gu...@python.org> wrote:
>
>
>> On Sat, Oct 16, 2021 at 12:21 PM David Mertz, Ph.D. <david.me...@gmail.com>
>> wrote:
>> I'm not making any claims about tuple creation speed vs. list creation on
>> microbenchmarks. It might we'll be 10% faster to create a million item tuple
>> than a million item list. Or maybe the opposite, I don't know.
>
> The thing to know about this (for everyone) is that creating a new tuple of
> known size requires a single allocation while creating a new list always
> requires two allocations. Where this really makes a difference is not when
> you have a million items but when you create thousands or millions of objects
> of modest size -- for lists it takes twice as many allocations.
>
> If the number of items is not known there are different strategies depending
> on what API you use; interestingly, the strategy deployed by
> PySequence_Tuple() has a comment claiming it "can grow a bit faster than for
> lists because unlike lists the over-allocation isn't permanent."
>
> Finally, the bytecode generated for (*a, *b) creates a list first and then
> turns that into a tuple (which will be allocated with the right size since
> it's known at that point).
>
> --
> --Guido van Rossum (python.org/~guido)
> Pronouns: he/him (why is my pronoun here?)
> _______________________________________________
> Python-ideas mailing list -- python-ideas@python.org
> To unsubscribe send an email to python-ideas-le...@python.org
> https://mail.python.org/mailman3/lists/python-ideas.python.org/
> Message archived at
> https://mail.python.org/archives/list/python-ideas@python.org/message/MNQBV6ORMV6DHUV44M524TCJHCLOBKI5/
> Code of Conduct: http://python.org/psf/codeofconduct/
_______________________________________________
Python-ideas mailing list -- python-ideas@python.org
To unsubscribe send an email to python-ideas-le...@python.org
https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
https://mail.python.org/archives/list/python-ideas@python.org/message/RL6ZNWIFRL57OVO7ADAGKRN3X2OIBAGV/
Code of Conduct: http://python.org/psf/codeofconduct/
