Python performance myths and fairy tales

#1

Post by todsacerdoti » Wed, Aug 06, 2025, 8:36 AM UTC

Python performance myths and fairy tales
lwn.net

Re: Python performance myths and fairy tales

#2

Post by NeutralForest » Wed, Aug 06, 2025, 10:16 AM UTC

Cool article, I think a lot of those issues are not Python specific so it's a good overview of whatever others can learn from a now 30 years old language! I think we'll probably go down the JS/TS route where another compiler (Pypy or mypyc or something else) will work alongside CPython but I don't see Python4 happening.

Re: Python performance myths and fairy tales

#3

Post by PontingClarke » Wed, Aug 06, 2025, 10:33 AM UTC

[dead]

Re: Python performance myths and fairy tales

#4

Post by tweakimp » Wed, Aug 06, 2025, 10:34 AM UTC

NeutralForest wrote: post #2

Cool article, I think a lot of those issues are not Python specific so it's a good overview of whatever others can learn from a now 30 years old language! I think we'll probably go down the JS/TS route where another compiler (Pypy or mypyc or something else) will work alongside CPython but I don't see Python4 happening.

I thought we would never see the GIL go away and yet, here we are. Never say never. Maybe Python4 is Python with another compiler.

Re: Python performance myths and fairy tales

#5

Post by 2d8a875f-39a2-4 » Wed, Aug 06, 2025, 10:40 AM UTC

Do you still need an add-on library to use more than one core?

Re: Python performance myths and fairy tales

#6

Post by writebetterc » Wed, Aug 06, 2025, 10:51 AM UTC

Good job on dispelling the myth of "compiler = fast". I hope SPython will be able to transfer some of its ideas to CPython with time.

Re: Python performance myths and fairy tales

#7

Post by quantumspandex » Wed, Aug 06, 2025, 10:55 AM UTC

So we are paying 99% of the performance just for the 1% of cases where it's nice to code in.

Why do people think it's a good trade-off?

Re: Python performance myths and fairy tales

#8

Post by BlackFly » Wed, Aug 06, 2025, 10:55 AM UTC

2d8a875f-39a2-4 wrote: post #5

Do you still need an add-on library to use more than one core?

Latest version officially supports full-threaded mode: https://docs.python.org/3.14/whatsnew/3.14.html#whatsnew314-...

Re: Python performance myths and fairy tales

#9

Post by nromiun » Wed, Aug 06, 2025, 10:59 AM UTC

quantumspandex wrote: post #7

So we are paying 99% of the performance just for the 1% of cases where it's nice to code in. Why do people think it's a good trade-off?

Because it's nice to code in. Not everything needs to scale or be fast.

Personally I think it is more crazy that you would optimize 99% of the time just to need it for 1% of the time.

Re: Python performance myths and fairy tales

#10

Post by dgfitz » Wed, Aug 06, 2025, 11:01 AM UTC

quantumspandex wrote: post #7

So we are paying 99% of the performance just for the 1% of cases where it's nice to code in. Why do people think it's a good trade-off?

I can say with certainty I’ve never paid a penny. Have you?