python: fix invalid return value for Node::setInitialVoltage()

Former-commit-id: e184629e

Include/dpsim/Python/Node.h

@@ -53,7 +53,7 @@ namespace Python {
 		static PyObject* voltage(PyObject *self, PyObject *args);
 		static PyObject* gnd(PyObject *self, PyObject *args);
 
-		static void setInitialVoltage(PyObject *self, PyObject *args, PyObject *kwds);
+		static PyObject* setInitialVoltage(PyObject *self, PyObject *args, PyObject *kwds);
 
 		static const char *name;
 		static const char *doc;

Source/Python/Node.cpp

@@ -163,7 +163,7 @@ const char* Python::Node<VarType>::docSetInitialVoltage =
 "set_initial_voltage\n"
 "Set the initial voltage at this node.\n";
 template<typename VarType>
-void Python::Node<VarType>::setInitialVoltage(PyObject *self, PyObject *args, PyObject *kwds) {
+PyObject* Python::Node<VarType>::setInitialVoltage(PyObject *self, PyObject *args, PyObject *kwds) {
 
 	Py_complex initVoltage;
 	CPS::Int phaseIndex;
@@ -171,10 +171,12 @@ void Python::Node<VarType>::setInitialVoltage(PyObject *self, PyObject *args, Py
 	static const char *kwlist[] = {"voltage", "index", nullptr};
 
 	if (!PyArg_ParseTupleAndKeywords(args, kwds, "Di", (char **) kwlist, &initVoltage, &phaseIndex))
-		return;
+		Py_RETURN_NONE;
 
 	Python::Node<VarType>* pyNode = (Python::Node<VarType>*) self;
 	pyNode->node->setInitialVoltage(CPS::Complex(initVoltage.real,initVoltage.imag), phaseIndex);
+
+	Py_RETURN_NONE;
 }
 
 template<typename VarType>