I am also facing the same issue; someone please provide the solution.

I used wrappy instead https://github.com/Dekken/wrappy/blob/plot/plot.cpp

I am running into the same issue on an Ubuntu machine with python 2.7, and numpy disabled. Has anybody found a solution, rather than using another wrapper/library?

I am running into the same issue (on Windows with Python 3.7 and numpy enabled).

Also, in case this is any help, if explicitly calling figure() before plotting (optional if only plotting to one figure), the std::runtime_error happens there: Call to figure() failed..

In all these cases, it seems like it is the call to

/* Call a callable Python object 'callable', with arguments given by the
   tuple 'args'.  If no arguments are needed, then 'args' can be NULL.

   Returns the result of the call on success, or NULL on failure.

   This is the equivalent of the Python expression:
   callable(*args). */
PyAPI_FUNC(PyObject *) PyObject_CallObject(PyObject *callable,
                                           PyObject *args);

that fails by returning NULL.

I think this is the issue I'm encountering. Putting PyErr_Print(); after the failed call indicated that sys.argv wasn't set.

Adding the following after Py_Initialize(); fixed it for me:

        wchar_t* args[1];
        args[0] = Py_DecodeLocale("", NULL); 
        PySys_SetArgv(0, args);