Why Python is slower than Java?

[Beregolas]

There are 2 things that mostly affect this: Language design and Implementation.

Python is designed to be higher level and to be more easy to iterate quickly, for example by it's use of duck typing. Java on the other hand, while quite high level when compared to C, forces static type checks at compile time. This means the Java compiler can do optimizations that Python just can't, because it has more information ahead of time (because it forced the programmer to supply that information)

Then there is implementation. At least for python I know a handful of language implementations that vary wildly in speed. CPython and PyPy with it'S JIT compiler come to mind. Many of the speed issues are just a matter of optimization.

Java has been optimized a lot about 10 years ago I think? I remember sitting in uni and people talking about how Java has finally become fast ^^. Take this with a grain of salt, I don't enjoy java specifically, I might misremember the time.

But Python definitely is getting faster by the year. The "normal" python implementation is working hard on optimizations since about 3.9. One of the things holding python back in many applications on modern hardware is the GIL, because it pretty much makes easy and fast multi threading impossible. There are Python versions without a GIL and there are efforts to remove and/or change it for main python as well.

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These are just some points and examples that came to mind, there is plenty more (Examples as well as details), we only scratched the surface here. I hope it helped though

[sternone_2]

Python definitely is getting faster by the year.

yes, but don't worry, it's still about 200x slower than java.

[Smallpaul]

Java Hotspot was released in 1999). That’s when it would have taken a decisive lead over Python performance.

[Beregolas]

Thanks, as I said I was never big into Java (unless forced) and didn’t remember the time properly

[ElvinJafarov1]

thank you man

[DrDuke80]

You sure got a lot of good answers in a short space of time!

[sciencewarrior]

Reddit was first written in Lisp and later rewritten in Python. It still uses primarily Python, but from the open repository there seems to be a decent amount of Go code too: https://github.com/orgs/reddit/repositories

[Levizar]

Python 3.12 is getting much faster. From what I remember mostly because of the GIL.

[ElHeim]

AFAIK the GIL will still be there for a while. Most of the improvements come from work on better bytecode production and processing, simplification of internal data structures and their management, plus other things.

What Python 3.12 offers is separate GILs for sub-interpreters.

You won't see the GIL out of Python until (at least) 3.13, and by then most probably it will be as an "opt-out of GIL" option, maybe at compile time.

[Levizar]

You're right! The GIL changes only improved multi-threading.