Embedding Python manually and using nanobind

[ktbarrett]

Based on #302 there doesn't seem to be any interest in adding support for interpreter embedding in nanobind. The questioner in that issue switched to using pybind11 as a solution, however I'm wondering if there's a better solution.

I am considering moving an existing library that's does the embedding and binding with handwritten C API calls, to nanobind. Is it possible to do the embedding with manual C API calls and then port the binding to nanobind? Are there assumptions that nanobind makes that would make this difficult or that I need to take into consideration?

[wjakob]

Nanobind has one global state inside the extension. This might cause problems if you spin up multiple interpreters. Other than that, doing things manually with the C API should be fine. I just do not want to support such use cases here, it is considered beyond the scope of this library.