To clarify, it is nuts that in an object method, there is a performance enhancement through caching a member value.

  class SomeClass
    def init(self)
      self.x = 0
    def SomeMethod(self)
      q = self.x
      ## do stuff with q, because otherwise you're dereferencing self.x all the damn time

That was how the Mojo language started. And then soon after the hype they said that being a superset of Python was no longer the goal. Probably because being a superset of Python is not a guarantee for performance either.

> python code could be so much faster if it didn't have to assume everything could change at any time

Definitely, but then it wouldn't be Python. One of the core principles of Python's design is to be extremely dynamic, and that anything can change at any time.

There are many other, pretty good, strictly dynamically typed languages which work just as well if not better than Python, for many purposes.

I have made some experiments with P2W, my experimental Python (subset) to WASM compiler. Initial figures are encouraging (5x speedup, on specific programs).

https://github.com/abilian/p2w

NB: some preliminary results:

  p2w is 4.03x SLOWER than gcc (geometric mean)

  p2w is 5.50x FASTER than cpython (geometric mean)

  p2w is 1.24x FASTER than pypy (geometric mean)

But that's just not what python is for. Move your performance-critical logic into a native module.

>> Sensible type-annotated python code could be so much faster if it didn't have to assume everything could change at any time.

Then it wouldn't be Python any more.

> Python really needs to take the Typescript approach of "all valid Python4 is valid Python3"

It is called type hints, and is already there. TS typing doesn't bring any perf benefits over plain JS.

I went sort of this route in an experiment with Claude.. I really want Python for .NET but I said, damn the expense, prioritize .NET compatibility, remove anything that isn't supported feasably. It means 0 python libs, but all of NuGet is supported. The rules are all signatures need types, and if you declare a type, it is that type, no exceptions, just like in C# (if you squint when looking at var in a funny way). I wound up with reasonable results, just a huge trade of the entire Python ecosystem for .NET with an insanely Python esque syntax.

Still churning on it, will probably publish it and do a proper blog post once I've built something interesting with the language itself.

Isn't rpython doing that, allowing changes on startup and then it's basically statically typed? Does it still exist? Was it ever production ready? I only once read a paper about it decades ago.

I think sadly a lot of Python in the wild relies heavily, somewhere, on the crazy unoptimisable stuff. For example pytest monkey patches everything everywhere all the time.

You could make this clean break and call it Python 4 but frankly I fear it won't be Python anymore.

> Python really needs to take the Typescript approach of "all valid Python4 is valid Python3

Great idea, but I'm not convinced that they learned anything from the Python 2 to 3 transition, so I wouldn't hold my breath.

If you want a language system without contempt for backward compatibility, you're probably better off with Java/C++/JavaScript/etc. (though using JS libraries is like building on quicksand.) Bit of a shame since I want to like Python/Rust/Swift/other modern-ish languages, but it turns out that formal language specifications were actually a pretty good idea. API stability is another.

SPy [1] is a new attempt at something like this.

TL;DR: SPy is a variant of Python specifically designed to be statically compilable while retaining a lot of the "useful" dynamic parts of Python.

The effort is led by Antonio Cuni, Principal Software Engineer at Anaconda. Still very early days but it seems promising to me.

[1] https://github.com/spylang/spy

There will be not Python 4, and 3.X policy requires forward compat, so we are already there.

Oh, and while we're at it, fix the "empty array is instantiated at parse time so all your functions with a default empty array argument share the same object" bullshit.