python library in simulink matlab system block

Hi, I am trying to create a matlab system block in simulink that imports and uses a python library.

After setting up the python environment, I tried the following in the resetImpl method in the matlab system block:

obj.cst = py.importlib.import_module('a valid python library reference')

But that gives me an error:

Function 'py.importlib.import_module' is not supported for code generation. Consider adding coder.extrinsic('py.importlib.import_module') at the top of the function to bypass code generation.'

So I tried to add coder.extrinsic according to the proposal in the error message:

coder.extrinsic('py.importlib.import_module');
obj.cst = py.importlib.import_module('a valid python library reference')

which results in the error:

'Cannot pass a mxArray to 'SystemProp_matlabCodegenValidateAnyProp'.'

Any suggestions?

[David Håkansson]

In many examples for coder.extrinsic, for example here the parameter needs to be pre-defined before running the extrinsic function. In that example it is on these lines:

y = 0;
y = mymin(N, D);

So that is easy when the data type that the mymin function returns is a double.

In my case I suspect I need to declare obj.cst as a python class before I call py.importlib.import_module. How to do that?