Different language means – C or C++

When we talk about extensions in different languages, we think almost exclusively about C and C++. Even tools such as Cython or Pyrex that provide Python language supersets only for the purpose of extensions are in fact source-to-source compilers that generate the C code from extended Python-like syntax.

It's true that you can use dynamic/shared libraries written in any language in Python if only such compilation is possible and so it goes a way beyond C and C++. But shared libraries are intrinsically generic. They can be used in any language that supports their loading. So, even if you write such a library in a completely different language (let's say Delphi or Prolog), it is hard to name such library a Python extension if it does not use the Python/C API.

Unfortunately, writing your own extensions only in C or C++ using the bare Python/C API is quite demanding. Not only because it requires a good understanding of one of the two languages that are relatively...