Raise a ZeroDivisionError exception from C++

[miklhh]

Hello!

We are writing a fixed-point arithmetic library for Python, using nanobind, and we would like to raise a ZeroDivisionError from C++ on division-by-zero using our custom fixed-point types. Can this be achieved using nanobind? I've seen ZeroDivisionError mentioned in the nanobind documentation under void register_exception_translator():

register_exception_translator(
    [](const std::exception_ptr &p, void * /*payload*/) {
        try {
            std::rethrow_exception(p);
        } catch (const ZeroDivisionException &e) {
            PyErr_SetString(PyExc_ZeroDivisionError, e.what());
        }
    }, nullptr /*payload*/);

but I don't understand if this is used to raise exceptions from C++. I haven't seen ZeroDivisionError mentioned throughout the pybind11 documentation either.

Can we raise the ZeroDivisionError from C++ using nanobind, and if so, how can we do this?

Best regards,
Mikael

[miklhh]

We ended up using this code snippet to throw Python ZeroDivisionError from C++. It appears to have the desired result when testing from Python.

APyFixed APyFixed::operator/(const APyFixed& rhs) const
{
    if (rhs.is_zero()) {
        PyErr_SetString(PyExc_ZeroDivisionError, "fixed-point division by zero");
        throw nb::python_error();
    }

    ...
}

Please let me know if mixing calls to the Python C-API like this together with nanobind can cause any trouble for us. Then I'll consider this question answered.