How to add new python type translation to ExternalEvaluate?

Question

Seems like Mathematica can only import basic types (lists, numpy objects, etc). Is there a way to tell Mathematica how to understand arbitrary python objects?

Answer 1

A class who inherits the WLSerializable class and overrides the to_wl method can be automatically converted.

from wolframclient.serializers.serializable import WLSerializable
from wolframclient.language import wl
from wolframclient.serializers import export

class MyPythonClass(WLSerializable):
    def __init__(self, *arguments):
        self.arguments = arguments

    def to_wl(self):
        return wl.YourWolframFunction(*self.arguments)

So we can use a wrap type to implement automatic conversion:

from sympy import Rational

class myRational(WLSerializable, Rational):
    def to_wl(self):
        return wl.Divide(self.p, self.q)

Here are some special binding packages, which can also be automatically converted: WolframResearch/WolframClientForPython

Answer 2

Developers say they provide an interface: Extending Serialization Writing an Encoder

Using as follows: