Pyrsistent VS xni

There are python libraries that implement Clojure style functional data types. Have you tried pyrsistent - https://github.com/tobgu/pyrsistent

Hissp is really interesting. Read through the docs and you'll understand Python more deeply. It works well with Toolz and Pyrsistent.

This is normal for some functional languages, since by definition they should prohibit assignment and hence mutation. But you can also achieve a similar (not the same) effect in python, using libraries like pyrsistent (https://github.com/tobgu/pyrsistent/)

It still is, and Cython is great for accelerating critical Python code.

A C extension is far preferable when you want to code in C, either to write a new data type[1], or write a Python frontend to a C library[2] that is too complex to be well supported by simple FFI.

I think people use Cython more internally when they value the maintainability of "mostly Python" over the fact that it's slower than what native C would get them.

[1]: https://github.com/tobgu/pyrsistent

[2]: https://github.com/libgit2/pygit2

There's Pyrsistent[1], which provides persistent data structures.

[1] https://github.com/tobgu/pyrsistent

We have this same problem in Ruby - implementing the Ruby C extension API if you aren't exactly the same as the reference Ruby implementation is extremely challenging. I think Charlie Nutter proposed something like this for Ruby in the past https://github.com/headius/xni.