[dagw]

Writing a much faster language runtime for a language that looks quite a bit like Python is easy. The hard problem is writing a faster language runtime that is 100% compatible with all current python programs (and their extensions) out in the world.

[throwaway894345]

I don't think 100% compatibility should be a goal. The maintainers really need to step up and guide the community through a tough but important transition (reducing the API surface for C-extensions to some sane subset so the implementation can be optimized--see things like h.py) or Python will remain in its very slow local optimum while the world moves around it.

Yes, we just went through one "tough but important" transition (Python 2->3) and it sucks to have to do this so often, but it's the price we pay from making bad bets (in this case, unnecessarily exposing the entire CPython interpreter as the C-extension API surface on the assumption that it will never be necessary to make CPython faster because people who need speed will just write the slow parts in C).

[coliveira]

But this is not necessary. The python developers just need to specify this fast subset of the language, and let people use to create libraries. Over time, we would have a growing set of libraries written in the fast subset.

[dagw]

People have. See PyPy and Pythran for two examples currently under active development. Instagram has such a project as well that they recently released. I know there have been others. None of them seem to catch on. It seems that most people don't actually want a faster subset of python. They want either all of python or none of python (by switching to another language all together)

[coliveira]

Pypy is not really practical. It requires you to stop using many features of Python. What Python needs is a fast subset that is supported within the main implementation.

[marky1991]

What do you mean? Pypy supports all of python. (not necessarily all of the C API, but that's somewhat a WIP and somewhat a result of the overly-expansive C API.)

[mumblemumble]

I'm not and have never been a game developer, but I think that a decent analogy here might be how many game studios write the core engine in C++, and then do a lot of the high level game logic and scripting in an interpreted language such as Lua or their own dialect of lisp.

I would guess that there's a clear separation of responsibilities, and each of the two languages is very well-suited to what it's being used for. There's not really a whole lot of anxiety about getting Lua (or whatever) to pull out all the stops you see in a compiler like SBCL or interpreter like V8, because these communities were never looking for a single language that could cover all uses cases in the first place. To steal an analogy I used the other day from myself, I'm guessing they don't want a spork all that badly because they're plenty happy with using a fork and a spoon.

That's how the community of people doing scientific computing and suchlike in Python tends to feel about things, too.

[travisoliphant]

This is related to the idea of EPython that we are working on (as we have funding): https://github.com/epython-dev/epython

It currently emits Cython for the C-backend (and PyIodide). It is very alpha currently, but if people are interested in helping, get in touch.