Improvements on error handling in the Python API.

21 files changed, 214 insertions, 288 deletions

diff --git a/source/blender/freestyle/intern/python/BPy_FrsMaterial.cpp b/source/blender/freestyle/intern/python/BPy_FrsMaterial.cpp
index 6f7d4ba5015..982318610a1 100644
--- a/source/blender/freestyle/intern/python/BPy_FrsMaterial.cpp
+++ b/source/blender/freestyle/intern/python/BPy_FrsMaterial.cpp
@@ -193,6 +193,7 @@ int FrsMaterial___init__(BPy_FrsMaterial *self, PyObject *args, PyObject *kwds)
 		self->m = new FrsMaterial(&f1, &f2, &f3, &f4, f5);
 
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid arguments");
 		return -1;
 	}
 
@@ -338,10 +339,8 @@ PyObject * FrsMaterial_shininess( BPy_FrsMaterial* self) {
 PyObject * FrsMaterial_setDiffuse( BPy_FrsMaterial *self, PyObject *args ) {
 	float f1, f2, f3, f4;
 
-	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  )) {
-		cout << "ERROR: FrsMaterial_setDiffuse" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  ))
+		return NULL;
 
 	self->m->setDiffuse(f1, f2, f3, f4);
 
@@ -351,10 +350,8 @@ PyObject * FrsMaterial_setDiffuse( BPy_FrsMaterial *self, PyObject *args ) {
 PyObject * FrsMaterial_setSpecular( BPy_FrsMaterial *self, PyObject *args ) {
 	float f1, f2, f3, f4;
 
-	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  )) {
-		cout << "ERROR: FrsMaterial_setSpecular" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  ))
+		return NULL;
 
 	self->m->setSpecular(f1, f2, f3, f4);
 
@@ -364,10 +361,8 @@ PyObject * FrsMaterial_setSpecular( BPy_FrsMaterial *self, PyObject *args ) {
 PyObject * FrsMaterial_setAmbient( BPy_FrsMaterial *self, PyObject *args ) {
 	float f1, f2, f3, f4;
 
-	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  )) {
-		cout << "ERROR: FrsMaterial_setAmbient" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  ))
+		return NULL;
 
 	self->m->setAmbient(f1, f2, f3, f4);
 
@@ -377,10 +372,8 @@ PyObject * FrsMaterial_setAmbient( BPy_FrsMaterial *self, PyObject *args ) {
 PyObject * FrsMaterial_setEmission( BPy_FrsMaterial *self, PyObject *args ) {
 	float f1, f2, f3, f4;
 
-	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  )) {
-		cout << "ERROR: FrsMaterial_setEmission" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "ffff", &f1, &f2, &f3, &f4)  ))
+		return NULL;
 
 	self->m->setEmission(f1, f2, f3, f4);
 
@@ -390,10 +383,8 @@ PyObject * FrsMaterial_setEmission( BPy_FrsMaterial *self, PyObject *args ) {
 PyObject * FrsMaterial_setShininess( BPy_FrsMaterial *self, PyObject *args ) {
 	float f;
 
-	if(!( PyArg_ParseTuple(args, "f", &f)  )) {
-		cout << "ERROR: FrsMaterial_setShininess" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "f", &f)  ))
+		return NULL;
 
 	self->m->setShininess(f);
 
diff --git a/source/blender/freestyle/intern/python/BPy_FrsNoise.cpp b/source/blender/freestyle/intern/python/BPy_FrsNoise.cpp
index a9989b13c6d..f27103c1ba2 100644
--- a/source/blender/freestyle/intern/python/BPy_FrsNoise.cpp
+++ b/source/blender/freestyle/intern/python/BPy_FrsNoise.cpp
@@ -1,5 +1,7 @@
 #include "BPy_FrsNoise.h"
 
+#include <sstream>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -152,10 +154,8 @@ PyObject * FrsNoise_turbulence1( BPy_FrsNoise *self , PyObject *args) {
 	float f1, f2, f3;
 	unsigned int i;
 
-	if(!( PyArg_ParseTuple(args, "fff|I", &f1, &f2, &f3, &i) )) {
-		cout << "ERROR: FrsNoise_turbulence1" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "fff|I", &f1, &f2, &f3, &i) ))
+		return NULL;
 
 	return PyFloat_FromDouble( self->n->turbulence1(f1, f2, f3, i) );
 }
@@ -165,9 +165,13 @@ PyObject * FrsNoise_turbulence2( BPy_FrsNoise *self , PyObject *args) {
 	float f2, f3;
 	unsigned int i;
 
-	if(!( PyArg_ParseTuple(args, "Off|I", &obj1, &f2, &f3, &i) && PyList_Check(obj1) && PyList_Size(obj1) > 1 )) {
-		cout << "ERROR: FrsNoise_turbulence2" << endl;
-		Py_RETURN_NONE;
+	if(!( PyArg_ParseTuple(args, "O!ff|I", &PyList_Type, &obj1, &f2, &f3, &i) ))
+		return NULL;
+	if( PyList_Size(obj1) != 2 ) {
+		stringstream msg("FrsNoise::turbulence2() accepts a list of 2 elements (");
+		msg << PyList_Size(obj1) << " found)";
+		PyErr_SetString(PyExc_TypeError, msg.str().c_str());
+		return NULL;
 	}
 
 	Vec2f v( PyFloat_AsDouble(PyList_GetItem(obj1, 0)), PyFloat_AsDouble(PyList_GetItem(obj1, 1)) );
@@ -180,9 +184,13 @@ PyObject * FrsNoise_turbulence3( BPy_FrsNoise *self , PyObject *args) {
 	float f2, f3;
 	unsigned int i;
 
-	if(!( PyArg_ParseTuple(args, "Off|I", &obj1, &f2, &f3, &i) && PyList_Check(obj1) && PyList_Size(obj1) > 2 )) {
-		cout << "ERROR: FrsNoise_turbulence3" << endl;
-		Py_RETURN_NONE;
+	if(!( PyArg_ParseTuple(args, "O!ff|I", &PyList_Type, &obj1, &f2, &f3, &i) ))
+		return NULL;
+	if( PyList_Size(obj1) != 3 ) {
+		stringstream msg("FrsNoise::turbulence3() accepts a list of 3 elements (");
+		msg << PyList_Size(obj1) << " found)";
+		PyErr_SetString(PyExc_TypeError, msg.str().c_str());
+		return NULL;
 	}
 
 	Vec3f v( PyFloat_AsDouble(PyList_GetItem(obj1, 0)),
@@ -195,10 +203,8 @@ PyObject * FrsNoise_turbulence3( BPy_FrsNoise *self , PyObject *args) {
 PyObject * FrsNoise_smoothNoise1( BPy_FrsNoise *self , PyObject *args) {
 	float f;
 
-	if(!( PyArg_ParseTuple(args, "f", &f) )) {
-		cout << "ERROR: FrsNoise_smoothNoise1" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "f", &f) ))
+		return NULL;
 
 	return PyFloat_FromDouble( self->n->smoothNoise1(f) );
 }
@@ -206,9 +212,13 @@ PyObject * FrsNoise_smoothNoise1( BPy_FrsNoise *self , PyObject *args) {
 PyObject * FrsNoise_smoothNoise2( BPy_FrsNoise *self , PyObject *args) {
 	PyObject *obj;
 
-	if(!( PyArg_ParseTuple(args, "O", &obj) && PyList_Check(obj) && PyList_Size(obj) > 1 )) {
-		cout << "ERROR: FrsNoise_smoothNoise2" << endl;
-		Py_RETURN_NONE;
+	if(!( PyArg_ParseTuple(args, "O", &PyList_Type, &obj) ))
+		return NULL;
+	if( PyList_Size(obj) != 2 ) {
+		stringstream msg("FrsNoise::smoothNoise2() accepts a list of 2 elements (");
+		msg << PyList_Size(obj) << " found)";
+		PyErr_SetString(PyExc_TypeError, msg.str().c_str());
+		return NULL;
 	}
 
 	Vec2f v( PyFloat_AsDouble(PyList_GetItem(obj, 0)), PyFloat_AsDouble(PyList_GetItem(obj, 1)) );
@@ -219,9 +229,13 @@ PyObject * FrsNoise_smoothNoise2( BPy_FrsNoise *self , PyObject *args) {
 PyObject * FrsNoise_smoothNoise3( BPy_FrsNoise *self , PyObject *args) {
 	PyObject *obj;
 
-	if(!( PyArg_ParseTuple(args, "O", &obj) && PyList_Check(obj) && PyList_Size(obj) > 2 )) {
-		cout << "ERROR: FrsNoise_smoothNoise3" << endl;
-		Py_RETURN_NONE;
+	if(!( PyArg_ParseTuple(args, "O", &PyList_Type, obj) ))
+		return NULL;
+	if( PyList_Size(obj) != 3 ) {
+		stringstream msg("FrsNoise::smoothNoise3() accepts a list of 3 elements (");
+		msg << PyList_Size(obj) << " found)";
+		PyErr_SetString(PyExc_TypeError, msg.str().c_str());
+		return NULL;
 	}
 
 	Vec3f v( PyFloat_AsDouble(PyList_GetItem(obj, 0)),
diff --git a/source/blender/freestyle/intern/python/BPy_Id.cpp b/source/blender/freestyle/intern/python/BPy_Id.cpp
index 7d8ea07d563..0396e4a36ff 100644
--- a/source/blender/freestyle/intern/python/BPy_Id.cpp
+++ b/source/blender/freestyle/intern/python/BPy_Id.cpp
@@ -165,10 +165,8 @@ PyObject *Id_getSecond( BPy_Id *self) {
 PyObject *Id_setFirst( BPy_Id *self , PyObject *args) {
 	unsigned int i;
 
-	if( !PyArg_ParseTuple(args, (char *)"i", &i) ) {
-		cout << "ERROR: Id_setFirst" << endl;
-		Py_RETURN_NONE;
-	}
+	if( !PyArg_ParseTuple(args, "i", &i) )
+		return NULL;
 
 	self->id->setFirst( i );
 
@@ -179,10 +177,8 @@ PyObject *Id_setFirst( BPy_Id *self , PyObject *args) {
 PyObject *Id_setSecond( BPy_Id *self , PyObject *args) {
 	unsigned int i;
 
-	if( !PyArg_ParseTuple(args, (char *)"i", &i) ) {
-		cout << "ERROR: Id_setSecond" << endl;
-		Py_RETURN_NONE;
-	}
+	if( !PyArg_ParseTuple(args, "i", &i) )
+		return NULL;
 
 	self->id->setSecond( i );
 
diff --git a/source/blender/freestyle/intern/python/Interface0D/CurvePoint/BPy_StrokeVertex.cpp b/source/blender/freestyle/intern/python/Interface0D/CurvePoint/BPy_StrokeVertex.cpp
index a62296a37d7..2c957dd7016 100644
--- a/source/blender/freestyle/intern/python/Interface0D/CurvePoint/BPy_StrokeVertex.cpp
+++ b/source/blender/freestyle/intern/python/Interface0D/CurvePoint/BPy_StrokeVertex.cpp
@@ -160,6 +160,7 @@ int StrokeVertex___init__(BPy_StrokeVertex *self, PyObject *args, PyObject *kwds
 										((BPy_StrokeVertex *) obj2)->sv,
 										PyFloat_AsDouble( obj3 ) );
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument(s)");
 		return -1;
 	}
 
@@ -202,10 +203,8 @@ PyObject * StrokeVertex_u( BPy_StrokeVertex *self ) {
 PyObject *StrokeVertex_setX( BPy_StrokeVertex *self , PyObject *args) {
 	double r;
 
-	if(!( PyArg_ParseTuple(args, "d", &r)  )) {
-		cout << "ERROR: StrokeVertex_setX" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "d", &r)  ))
+		return NULL;
 
 	self->sv->setX( r );
 
@@ -215,10 +214,8 @@ PyObject *StrokeVertex_setX( BPy_StrokeVertex *self , PyObject *args) {
 PyObject *StrokeVertex_setY( BPy_StrokeVertex *self , PyObject *args) {
 	double r;
 
-	if(!( PyArg_ParseTuple(args, "d", &r)  )) {
-		cout << "ERROR: StrokeVertex_setY" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "d", &r)  ))
+		return NULL;
 
 	self->sv->setY( r );
 
@@ -229,33 +226,34 @@ PyObject *StrokeVertex_setY( BPy_StrokeVertex *self , PyObject *args) {
 PyObject *StrokeVertex_setPoint( BPy_StrokeVertex *self , PyObject *args) {
 	PyObject *obj1 = 0, *obj2 = 0;
 
-	if(!( PyArg_ParseTuple(args, "O|O", &obj1, &obj2) )) {
-		cout << "ERROR: StrokeVertex_setPoint" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O|O", &obj1, &obj2) ))
+		return NULL;
 	
 	if( PyList_Check(obj1) && !obj2 ){
 		if ( PyList_Size(obj1) != 2 ) {
-			cout << "Error: StrokeVertex::setPoint() accepts a list of 2 elements ("
-			     << PyList_Size(obj1) << " found)" << endl;
-			Py_RETURN_NONE;
+			stringstream msg("StrokeVertex::setPoint() accepts a list of 2 elements (");
+			msg << PyList_Size(obj1) << " found)";
+			PyErr_SetString(PyExc_TypeError, msg.str().c_str());
+			return NULL;
 		}
 		Vec2f v( 	PyFloat_AsDouble( PyList_GetItem(obj1, 0) ),
 					PyFloat_AsDouble( PyList_GetItem(obj1, 1) )  );
 		self->sv->setPoint( v );
 	} else if ( VectorObject_Check(obj1) && !obj2) {
 		if ( ((VectorObject *)obj1)->size != 2 ) {
-			cout << "Error: StrokeVertex::setPoint() accepts a vector of 2 elements ("
-			     << ((VectorObject *)obj1)->size << " found)" << endl;
-			Py_RETURN_NONE;
+			stringstream msg("StrokeVertex::setPoint() accepts a vector of 2 elements (");
+			msg << ((VectorObject *)obj1)->size << " found)";
+			PyErr_SetString(PyExc_TypeError, msg.str().c_str());
+			return NULL;
 		}
 		Vec2f *v = Vec2f_ptr_from_Vector( obj1 );
 		self->sv->setPoint( *v );
 		delete v; 
-	} else if( obj1 && obj2 ){
+	} else if( PyFloat_Check(obj1) && obj2 && PyFloat_Check(obj2) ){
 		self->sv->setPoint( PyFloat_AsDouble(obj1), PyFloat_AsDouble(obj2) );
 	} else {
-		cout << "Error: StrokeVertex::setPoint(): unknown argument type" << endl;
+		PyErr_SetString(PyExc_TypeError, "StrokeVertex::setPoint(): unknown argument type");
+		return NULL;
 	}
 
 	Py_RETURN_NONE;
@@ -264,10 +262,8 @@ PyObject *StrokeVertex_setPoint( BPy_StrokeVertex *self , PyObject *args) {
 PyObject *StrokeVertex_setAttribute( BPy_StrokeVertex *self , PyObject *args) {
 	PyObject *py_sa;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_sa) && BPy_StrokeAttribute_Check(py_sa)  )) {
-		cout << "ERROR: StrokeVertex_setAttribute" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &StrokeAttribute_Type, &py_sa) ))
+		return NULL;
 
 	self->sv->setAttribute(*( ((BPy_StrokeAttribute *) py_sa)->sa ));
 
@@ -277,10 +273,8 @@ PyObject *StrokeVertex_setAttribute( BPy_StrokeVertex *self , PyObject *args) {
 PyObject *StrokeVertex_setCurvilinearAbscissa( BPy_StrokeVertex *self , PyObject *args) {
 	double r;
 
-	if(!( PyArg_ParseTuple(args, "d", &r)  )) {
-		cout << "ERROR: StrokeVertex_setCurvilinearAbscissa" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "d", &r)  ))
+		return NULL;
 
 	self->sv->setCurvilinearAbscissa( r );
 
@@ -291,10 +285,8 @@ PyObject *StrokeVertex_setCurvilinearAbscissa( BPy_StrokeVertex *self , PyObject
 PyObject *StrokeVertex_setStrokeLength( BPy_StrokeVertex *self , PyObject *args) {
 	double r;
 
-	if(!( PyArg_ParseTuple(args, "d", &r)  )) {
-		cout << "ERROR: StrokeVertex_setStrokeLength" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "d", &r)  ))
+		return NULL;
 
 	self->sv->setStrokeLength( r );
 
diff --git a/source/blender/freestyle/intern/python/Interface1D/BPy_FEdge.cpp b/source/blender/freestyle/intern/python/Interface1D/BPy_FEdge.cpp
index 0718c18b253..1773e86c065 100644
--- a/source/blender/freestyle/intern/python/Interface1D/BPy_FEdge.cpp
+++ b/source/blender/freestyle/intern/python/Interface1D/BPy_FEdge.cpp
@@ -163,6 +163,7 @@ int FEdge___init__(BPy_FEdge *self, PyObject *args, PyObject *kwds)
 	} else if( BPy_SVertex_Check(obj1) && BPy_SVertex_Check(obj2) ) {
 		self->fe = new FEdge( ((BPy_SVertex *) obj1)->sv, ((BPy_SVertex *) obj2)->sv );
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument(s)");
 		return -1;
 	}
 
@@ -203,9 +204,11 @@ PyObject * FEdge_vertexB( BPy_FEdge *self ) {
 PyObject * FEdge___getitem__( BPy_FEdge *self, PyObject *args ) {
 	int i;
 
-	if(!( PyArg_ParseTuple(args, "i", &i) && (i == 0 || i == 1)  )) {
-		cout << "ERROR: FEdge___getitem__" << endl;
-		Py_RETURN_NONE;
+	if(!( PyArg_ParseTuple(args, "i", &i) ))
+		return NULL;
+	if(!(i == 0 || i == 1)) {
+		PyErr_SetString(PyExc_IndexError, "index must be either 0 or 1");
+		return NULL;
 	}
 	
 	if( SVertex *v = self->fe->operator[](i) )
@@ -242,10 +245,8 @@ PyObject * FEdge_isSmooth( BPy_FEdge *self ) {
 PyObject *FEdge_setVertexA( BPy_FEdge *self , PyObject *args) {
 	PyObject *py_sv;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_sv) && BPy_SVertex_Check(py_sv) )) {
-		cout << "ERROR: FEdge_setVertexA" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &SVertex_Type, &py_sv) ))
+		return NULL;
 
 	self->fe->setVertexA( ((BPy_SVertex *) py_sv)->sv );
 
@@ -268,10 +269,8 @@ PyObject *FEdge_setVertexB( BPy_FEdge *self , PyObject *args) {
 PyObject *FEdge_setId( BPy_FEdge *self , PyObject *args) {
 	PyObject *py_id;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_id) && BPy_Id_Check(py_id) )) {
-		cout << "ERROR: FEdge_setId" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &Id_Type, &py_id) ))
+		return NULL;
 
 	self->fe->setId(*( ((BPy_Id *) py_id)->id ));
 
@@ -282,10 +281,8 @@ PyObject *FEdge_setId( BPy_FEdge *self , PyObject *args) {
 PyObject *FEdge_setNextEdge( BPy_FEdge *self , PyObject *args) {
 	PyObject *py_fe;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_fe) && BPy_FEdge_Check(py_fe) )) {
-		cout << "ERROR: FEdge_setNextEdge" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &FEdge_Type, &py_fe) ))
+		return NULL;
 
 	self->fe->setNextEdge( ((BPy_FEdge *) py_fe)->fe );
 
@@ -295,10 +292,8 @@ PyObject *FEdge_setNextEdge( BPy_FEdge *self , PyObject *args) {
 PyObject *FEdge_setPreviousEdge( BPy_FEdge *self , PyObject *args) {
 	PyObject *py_fe;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_fe) && BPy_FEdge_Check(py_fe) )) {
-		cout << "ERROR: FEdge_setPreviousEdge" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &FEdge_Type, &py_fe) ))
+		return NULL;
 
 	self->fe->setPreviousEdge( ((BPy_FEdge *) py_fe)->fe );
 
@@ -308,10 +303,8 @@ PyObject *FEdge_setPreviousEdge( BPy_FEdge *self , PyObject *args) {
 PyObject * FEdge_setNature( BPy_FEdge *self, PyObject *args ) {
 	PyObject *py_n;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_n) && BPy_Nature_Check(py_n) )) {
-		cout << "ERROR: FEdge_setNature" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &Nature_Type, &py_n) ))
+		return NULL;
 	
 	PyObject *i = (PyObject *) &( ((BPy_Nature *) py_n)->i );
 	self->fe->setNature( PyInt_AsLong(i) );
@@ -323,10 +316,8 @@ PyObject * FEdge_setNature( BPy_FEdge *self, PyObject *args ) {
 PyObject * FEdge_setViewEdge( BPy_FEdge *self, PyObject *args ) {
 	PyObject *py_ve;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_ve) && BPy_ViewEdge_Check(py_ve) )) {
-		cout << "ERROR: FEdge_setViewEdge" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &ViewEdge_Type, &py_ve) ))
+		return NULL;
 
 	ViewEdge *ve = ((BPy_ViewEdge *) py_ve)->ve;
 	self->fe->setViewEdge( ve );
@@ -339,10 +330,8 @@ PyObject * FEdge_setViewEdge( BPy_FEdge *self, PyObject *args ) {
 PyObject *FEdge_setSmooth( BPy_FEdge *self , PyObject *args) {
 	PyObject *py_b;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_b) && PyBool_Check(py_b) )) {
-		cout << "ERROR: FEdge_setSmooth" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &PyBool_Type, &py_b) ))
+		return NULL;
 
 	self->fe->setSmooth( bool_from_PyBool(py_b) );
 
@@ -364,10 +353,8 @@ PyObject * FEdge_verticesEnd( BPy_FEdge *self ) {
 PyObject * FEdge_pointsBegin( BPy_FEdge *self, PyObject *args ) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: FEdge_pointsBegin" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->fe->pointsBegin(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
@@ -376,10 +363,8 @@ PyObject * FEdge_pointsBegin( BPy_FEdge *self, PyObject *args ) {
 PyObject * FEdge_pointsEnd( BPy_FEdge *self, PyObject *args ) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: FEdge_pointsEnd" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->fe->pointsEnd(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
diff --git a/source/blender/freestyle/intern/python/Interface1D/BPy_FrsCurve.cpp b/source/blender/freestyle/intern/python/Interface1D/BPy_FrsCurve.cpp
index 1506092511a..541391e05a7 100644
--- a/source/blender/freestyle/intern/python/Interface1D/BPy_FrsCurve.cpp
+++ b/source/blender/freestyle/intern/python/Interface1D/BPy_FrsCurve.cpp
@@ -138,18 +138,13 @@ int FrsCurve___init__(BPy_FrsCurve *self, PyObject *args, PyObject *kwds)
 		self->c = new Curve();
 		
 	} else if( BPy_FrsCurve_Check(obj) ) {
-		if( ((BPy_FrsCurve *) obj)->c )
-			self->c = new Curve(*( ((BPy_FrsCurve *) obj)->c ));
-		else
-			return -1;
+		self->c = new Curve(*( ((BPy_FrsCurve *) obj)->c ));
 		
 	} else if( BPy_Id_Check(obj) ) {
-		if( ((BPy_Id *) obj)->id )
-			self->c = new Curve(*( ((BPy_Id *) obj)->id ));
-		else
-			return -1;
+		self->c = new Curve(*( ((BPy_Id *) obj)->id ));
 			
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
 		return -1;
 	}
 
@@ -162,37 +157,39 @@ int FrsCurve___init__(BPy_FrsCurve *self, PyObject *args, PyObject *kwds)
 PyObject * FrsCurve_push_vertex_back( BPy_FrsCurve *self, PyObject *args ) {
 	PyObject *obj;
 
-	if(!( PyArg_ParseTuple(args, "O", &obj) )) {
-		cout << "ERROR: FrsCurve_push_vertex_back" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O", &obj) ))
+		return NULL;
 
 	if( BPy_CurvePoint_Check(obj) ) {
 		self->c->push_vertex_back( ((BPy_CurvePoint *) obj)->cp );
 	} else if( BPy_SVertex_Check(obj) ) {
 		self->c->push_vertex_back( ((BPy_SVertex *) obj)->sv );
+	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
+		return NULL;
 	}
 
 	Py_RETURN_NONE;
 }
 
 PyObject * FrsCurve_push_vertex_front( BPy_FrsCurve *self, PyObject *args ) {
-		PyObject *obj;
-
-		if(!( PyArg_ParseTuple(args, "O", &obj) )) {
-			cout << "ERROR: FrsCurve_push_vertex_front" << endl;
-			Py_RETURN_NONE;
-		}
+	PyObject *obj;
 
-		if( BPy_CurvePoint_Check(obj) ) {
-			self->c->push_vertex_front( ((BPy_CurvePoint *) obj)->cp );
-		} else if( BPy_SVertex_Check(obj) ) {
-			self->c->push_vertex_front( ((BPy_SVertex *) obj)->sv );
-		}
+	if(!( PyArg_ParseTuple(args, "O", &obj) ))
+		return NULL;
 
-		Py_RETURN_NONE;
+	if( BPy_CurvePoint_Check(obj) ) {
+		self->c->push_vertex_front( ((BPy_CurvePoint *) obj)->cp );
+	} else if( BPy_SVertex_Check(obj) ) {
+		self->c->push_vertex_front( ((BPy_SVertex *) obj)->sv );
+	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
+		return NULL;
 	}
 
+	Py_RETURN_NONE;
+}
+
 PyObject * FrsCurve_empty( BPy_FrsCurve *self ) {
 	return PyBool_from_bool( self->c->empty() );
 }
@@ -219,10 +216,8 @@ PyObject * FrsCurve_verticesEnd( BPy_FrsCurve *self ) {
 PyObject * FrsCurve_pointsBegin( BPy_FrsCurve *self, PyObject *args ) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: FEdge_pointsBegin" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->c->pointsBegin(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
@@ -231,10 +226,8 @@ PyObject * FrsCurve_pointsBegin( BPy_FrsCurve *self, PyObject *args ) {
 PyObject * FrsCurve_pointsEnd( BPy_FrsCurve *self, PyObject *args ) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: FEdge_pointsEnd" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->c->pointsEnd(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
diff --git a/source/blender/freestyle/intern/python/Interface1D/BPy_Stroke.cpp b/source/blender/freestyle/intern/python/Interface1D/BPy_Stroke.cpp
index d9f46774929..f7c5e261db5 100644
--- a/source/blender/freestyle/intern/python/Interface1D/BPy_Stroke.cpp
+++ b/source/blender/freestyle/intern/python/Interface1D/BPy_Stroke.cpp
@@ -45,7 +45,7 @@ static PyObject * Stroke_pointsEnd( BPy_Stroke *self , PyObject *args);
 static PyMethodDef BPy_Stroke_methods[] = {	
 	{"__getitem__", ( PyCFunction ) Stroke___getitem__, METH_O, "(int i) Returns the i-th StrokeVertex constituting the Stroke."},
 	{"ComputeSampling", ( PyCFunction ) Stroke_ComputeSampling, METH_VARARGS, "(int nVertices) Compute the sampling needed to get nVertices vertices. If the specified number of vertices is less than the actual number of vertices, the actual sampling value is returned."},
-		{"Resample", ( PyCFunction ) Stroke_Resample, METH_VARARGS, "(float f | int n) Resampling method. If the argument is a float, Resamples the curve with a given sampling; if this sampling is < to the actual sampling value, no resampling is done. If the argument is an integer, Resamples the curve so that it eventually has n. That means it is going to add n-vertices_size, if vertices_size is the number of points we already have. Is vertices_size >= n, no resampling is done."},
+	{"Resample", ( PyCFunction ) Stroke_Resample, METH_VARARGS, "(float f | int n) Resampling method. If the argument is a float, Resamples the curve with a given sampling; if this sampling is < to the actual sampling value, no resampling is done. If the argument is an integer, Resamples the curve so that it eventually has n. That means it is going to add n-vertices_size, if vertices_size is the number of points we already have. Is vertices_size >= n, no resampling is done."},
 	{"RemoveVertex", ( PyCFunction ) Stroke_RemoveVertex, METH_VARARGS, "(StrokeVertex sv) Removes the stroke vertex sv from the stroke. The length and curvilinear abscissa are updated consequently."},
 	{"InsertVertex", ( PyCFunction ) Stroke_InsertVertex, METH_VARARGS, "(StrokeVertex sv, StrokeVertexIterator next) Inserts the stroke vertex iVertex in the stroke before next. The length, curvilinear abscissa are updated consequently."},
 	{"getMediumType", ( PyCFunction ) Stroke_getMediumType, METH_NOARGS, "() Returns the MediumType used for this Stroke."},
@@ -241,10 +241,8 @@ PyObject * Stroke___getitem__( BPy_Stroke *self, PyObject *item ) {
 PyObject * Stroke_ComputeSampling( BPy_Stroke *self, PyObject *args ) {	
 	int i;
 
-	if(!( PyArg_ParseTuple(args, "i", &i)  )) {
-		cout << "ERROR: Stroke_ComputeSampling" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "i", &i)  ))
+		return NULL;
 
 	return PyFloat_FromDouble( self->s->ComputeSampling( i ) );
 }
@@ -252,15 +250,17 @@ PyObject * Stroke_ComputeSampling( BPy_Stroke *self, PyObject *args ) {
 PyObject * Stroke_Resample( BPy_Stroke *self, PyObject *args ) {	
 	PyObject *obj;
 
-	if(!( PyArg_ParseTuple(args, "O", &obj) )) {
-		cout << "ERROR: Stroke_Resample" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O", &obj) ))
+		return NULL;
 
 	if( PyInt_Check(obj) )
 		self->s->Resample( (int) PyInt_AsLong(obj) );
 	else if( PyFloat_Check(obj) )
 		self->s->Resample( (float) PyFloat_AsDouble(obj) );
+	else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
+		return NULL;
+	}
 		
 	Py_RETURN_NONE;
 }
@@ -268,11 +268,8 @@ PyObject * Stroke_Resample( BPy_Stroke *self, PyObject *args ) {
 PyObject * Stroke_InsertVertex( BPy_Stroke *self, PyObject *args ) {
 	PyObject *py_sv = 0, *py_sv_it = 0;
 
-	if(!( PyArg_ParseTuple(args, "OO", &py_sv, &py_sv_it) &&
-			BPy_StrokeVertex_Check(py_sv) && BPy_StrokeVertexIterator_Check(py_sv_it) )) {
-		cout << "ERROR: Stroke_InsertVertex" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!O!", &StrokeVertex_Type, &py_sv, &StrokeVertexIterator_Type, &py_sv_it) ))
+		return NULL;
 
 	StrokeVertex *sv = ((BPy_StrokeVertex *) py_sv)->sv;
 	StrokeInternal::StrokeVertexIterator sv_it(*( ((BPy_StrokeVertexIterator *) py_sv_it)->sv_it ));
@@ -284,13 +281,15 @@ PyObject * Stroke_InsertVertex( BPy_Stroke *self, PyObject *args ) {
 PyObject * Stroke_RemoveVertex( BPy_Stroke *self, PyObject *args ) {	
 	PyObject *py_sv;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_sv) )) {
-		cout << "ERROR: Stroke_RemoveVertex" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &StrokeVertex_Type, &py_sv) ))
+		return NULL;
 
-	if( BPy_StrokeVertex_Check(py_sv) && ((BPy_StrokeVertex *) py_sv)->sv )
+	if( ((BPy_StrokeVertex *) py_sv)->sv )
 		self->s->RemoveVertex( ((BPy_StrokeVertex *) py_sv)->sv );
+	else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
+		return NULL;
+	}
 		
 	Py_RETURN_NONE;
 }
@@ -311,13 +310,10 @@ PyObject * Stroke_hasTips( BPy_Stroke *self ) {
 PyObject *Stroke_setId( BPy_Stroke *self , PyObject *args) {
 	PyObject *py_id;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_id) && BPy_Id_Check(py_id)  )) {
-		cout << "ERROR: Stroke_setId" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &Id_Type, &py_id) ))
+		return NULL;
 
-	if( ((BPy_Id *) py_id)->id )
-		self->s->setId(*( ((BPy_Id *) py_id)->id ));
+	self->s->setId(*( ((BPy_Id *) py_id)->id ));
 
 	Py_RETURN_NONE;
 }
@@ -325,10 +321,8 @@ PyObject *Stroke_setId( BPy_Stroke *self , PyObject *args) {
 PyObject *Stroke_setLength( BPy_Stroke *self , PyObject *args) {
 	float f;
 
-	if(!( PyArg_ParseTuple(args, "f", &f) )) {
-		cout << "ERROR: Stroke_setLength" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "f", &f) ))
+		return NULL;
 
 	self->s->setLength( f );
 
@@ -338,10 +332,8 @@ PyObject *Stroke_setLength( BPy_Stroke *self , PyObject *args) {
 PyObject *Stroke_setMediumType( BPy_Stroke *self , PyObject *args) {
 	PyObject *py_mt;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_mt) && BPy_MediumType_Check(py_mt)  )) {
-		cout << "ERROR: Stroke_setMediumType" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &MediumType_Type, &py_mt) ))
+		return NULL;
 
 	self->s->setMediumType( static_cast<Stroke::MediumType>(PyInt_AsLong(py_mt)) );
 
@@ -351,10 +343,8 @@ PyObject *Stroke_setMediumType( BPy_Stroke *self , PyObject *args) {
 PyObject *Stroke_setTextureId( BPy_Stroke *self , PyObject *args) {
 	unsigned int i;
 
-	if(!( PyArg_ParseTuple(args, "I", &i) )) {
-		cout << "ERROR: Stroke_setTextureId" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "I", &i) ))
+		return NULL;
 
 	self->s->setTextureId( i );
 
@@ -364,10 +354,8 @@ PyObject *Stroke_setTextureId( BPy_Stroke *self , PyObject *args) {
 PyObject *Stroke_setTips( BPy_Stroke *self , PyObject *args) {
 	PyObject *py_b;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_b) && PyBool_Check(py_b)  )) {
-		cout << "ERROR: Stroke_setTips" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &PyBool_Type, &py_b) ))
+		return NULL;
 
 	self->s->setTips( bool_from_PyBool(py_b) );
 
@@ -377,10 +365,9 @@ PyObject *Stroke_setTips( BPy_Stroke *self , PyObject *args) {
 PyObject * Stroke_strokeVerticesBegin( BPy_Stroke *self , PyObject *args) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )){
-		cout << "ERROR: Stroke_pointsBegin" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
+
 	StrokeInternal::StrokeVertexIterator sv_it( self->s->strokeVerticesBegin(f) );
 	return BPy_StrokeVertexIterator_from_StrokeVertexIterator( sv_it, 0 );
 }
@@ -407,10 +394,8 @@ PyObject * Stroke_verticesEnd( BPy_Stroke *self ) {
 PyObject * Stroke_pointsBegin( BPy_Stroke *self , PyObject *args) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: Stroke_pointsBegin" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 
 	Interface0DIterator if0D_it( self->s->pointsBegin(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
@@ -419,10 +404,8 @@ PyObject * Stroke_pointsBegin( BPy_Stroke *self , PyObject *args) {
 PyObject * Stroke_pointsEnd( BPy_Stroke *self , PyObject *args) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: Stroke_pointsEnd" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->s->pointsEnd(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
diff --git a/source/blender/freestyle/intern/python/Interface1D/BPy_ViewEdge.cpp b/source/blender/freestyle/intern/python/Interface1D/BPy_ViewEdge.cpp
index e32b90a2382..8ac65edde89 100644
--- a/source/blender/freestyle/intern/python/Interface1D/BPy_ViewEdge.cpp
+++ b/source/blender/freestyle/intern/python/Interface1D/BPy_ViewEdge.cpp
@@ -225,10 +225,8 @@ PyObject * ViewEdge_getChainingTimeStamp( BPy_ViewEdge *self ) {
 PyObject * ViewEdge_setChainingTimeStamp( BPy_ViewEdge *self, PyObject *args) {
 	int timestamp = 0 ;
 
-	if( !PyArg_ParseTuple(args, "i", &timestamp) ) {
-		cout << "ERROR: ViewEdge_setChainingTimeStamp" << endl;
-		Py_RETURN_NONE;
-	}
+	if( !PyArg_ParseTuple(args, "i", &timestamp) )
+		return NULL;
 	
 	self->ve->setChainingTimeStamp( timestamp );
 
@@ -238,10 +236,8 @@ PyObject * ViewEdge_setChainingTimeStamp( BPy_ViewEdge *self, PyObject *args) {
 PyObject *ViewEdge_setA( BPy_ViewEdge *self , PyObject *args) {
 	PyObject *py_vv;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_vv) && BPy_ViewVertex_Check(py_vv) )) {
-		cout << "ERROR: ViewEdge_setA" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &ViewVertex_Type, &py_vv) ))
+		return NULL;
 
 	self->ve->setA( ((BPy_ViewVertex *) py_vv)->vv );
 
@@ -251,10 +247,8 @@ PyObject *ViewEdge_setA( BPy_ViewEdge *self , PyObject *args) {
 PyObject *ViewEdge_setB( BPy_ViewEdge *self , PyObject *args) {
 	PyObject *py_vv;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_vv) && BPy_ViewVertex_Check(py_vv) )) {
-		cout << "ERROR: ViewEdge_setB" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &ViewVertex_Type, &py_vv) ))
+		return NULL;
 
 	self->ve->setB( ((BPy_ViewVertex *) py_vv)->vv );
 
@@ -264,10 +258,8 @@ PyObject *ViewEdge_setB( BPy_ViewEdge *self , PyObject *args) {
 PyObject * ViewEdge_setNature( BPy_ViewEdge *self, PyObject *args ) {
 	PyObject *py_n;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_n) && BPy_Nature_Check(py_n) )) {
-		cout << "ERROR: ViewEdge_setNature" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &Nature_Type, &py_n) ))
+		return NULL;
 	
 	PyObject *i = (PyObject *) &( ((BPy_Nature *) py_n)->i );
 	self->ve->setNature( PyInt_AsLong(i) );
@@ -278,10 +270,8 @@ PyObject * ViewEdge_setNature( BPy_ViewEdge *self, PyObject *args ) {
 PyObject * ViewEdge_setFEdgeA( BPy_ViewEdge *self, PyObject *args ) {
 	PyObject *py_fe;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_fe) && BPy_FEdge_Check(py_fe) )) {
-		cout << "ERROR: ViewEdge_setFEdgeA" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &FEdge_Type, &py_fe) ))
+		return NULL;
 
 	self->ve->setFEdgeA( ((BPy_FEdge *) py_fe)->fe );
 
@@ -291,10 +281,8 @@ PyObject * ViewEdge_setFEdgeA( BPy_ViewEdge *self, PyObject *args ) {
 PyObject * ViewEdge_setFEdgeB( BPy_ViewEdge *self, PyObject *args ) {
 	PyObject *py_fe;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_fe) && BPy_FEdge_Check(py_fe) )) {
-		cout << "ERROR: ViewEdge_setFEdgeB" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &FEdge_Type, &py_fe) ))
+		return NULL;
 
 	self->ve->setFEdgeB( ((BPy_FEdge *) py_fe)->fe );
 
@@ -304,10 +292,8 @@ PyObject * ViewEdge_setFEdgeB( BPy_ViewEdge *self, PyObject *args ) {
 PyObject * ViewEdge_setShape( BPy_ViewEdge *self, PyObject *args ) {
 	PyObject *py_vs;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_vs) && BPy_ViewShape_Check(py_vs) )) {
-		cout << "ERROR: ViewEdge_setShape" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O", &ViewShape_Type, &py_vs) ))
+		return NULL;
 
 	self->ve->setShape( ((BPy_ViewShape *) py_vs)->vs );
 
@@ -317,10 +303,8 @@ PyObject * ViewEdge_setShape( BPy_ViewEdge *self, PyObject *args ) {
 PyObject * ViewEdge_setId( BPy_ViewEdge *self, PyObject *args ) {
 	PyObject *py_id;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_id) && BPy_Id_Check(py_id) )) {
-		cout << "ERROR: ViewEdge_setId" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &Id_Type, &py_id) ))
+		return NULL;
 
 	Id id(*( ((BPy_Id *) py_id)->id ));
 	self->ve->setId( id );
@@ -337,10 +321,8 @@ PyObject * ViewEdge_UpdateFEdges( BPy_ViewEdge *self ) {
 PyObject * ViewEdge_setaShape( BPy_ViewEdge *self, PyObject *args ) {
 	PyObject *py_vs;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_vs) && BPy_ViewShape_Check(py_vs) )) {
-		cout << "ERROR: ViewEdge_setaShape" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &ViewShape_Type, &py_vs) ))
+		return NULL;
 
 	ViewShape *vs = ((BPy_ViewShape *) py_vs)->vs;
 	self->ve->setaShape( vs );
@@ -351,10 +333,8 @@ PyObject * ViewEdge_setaShape( BPy_ViewEdge *self, PyObject *args ) {
 PyObject * ViewEdge_setQI( BPy_ViewEdge *self, PyObject *args ) {
 	int qi;
 
-	if(!( PyArg_ParseTuple(args, "i", &qi) )) {
-		cout << "ERROR: ViewEdge_setQI" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "i", &qi) ))
+		return NULL;
 
 	self->ve->setQI( qi );
 
@@ -375,10 +355,8 @@ PyObject * ViewEdge_verticesEnd( BPy_ViewEdge *self ) {
 PyObject * ViewEdge_pointsBegin( BPy_ViewEdge *self, PyObject *args ) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: ViewEdge_pointsBegin" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->ve->pointsBegin(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
@@ -387,10 +365,8 @@ PyObject * ViewEdge_pointsBegin( BPy_ViewEdge *self, PyObject *args ) {
 PyObject * ViewEdge_pointsEnd( BPy_ViewEdge *self, PyObject *args ) {
 	float f = 0;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
-		cout << "ERROR: ViewEdge_pointsEnd" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "|f", &f)  ))
+		return NULL;
 	
 	Interface0DIterator if0D_it( self->ve->pointsEnd(f) );
 	return BPy_Interface0DIterator_from_Interface0DIterator( if0D_it );
diff --git a/source/blender/freestyle/intern/python/Interface1D/Curve/BPy_Chain.cpp b/source/blender/freestyle/intern/python/Interface1D/Curve/BPy_Chain.cpp
index 12c79743559..f30b2bbdd96 100644
--- a/source/blender/freestyle/intern/python/Interface1D/Curve/BPy_Chain.cpp
+++ b/source/blender/freestyle/intern/python/Interface1D/Curve/BPy_Chain.cpp
@@ -125,18 +125,13 @@ int Chain___init__(BPy_Chain *self, PyObject *args, PyObject *kwds)
 		self->c = new Chain();
 		
 	} else if( BPy_Chain_Check(obj) ) {
-		if( ((BPy_Chain *) obj)->c )
-			self->c = new Chain(*( ((BPy_Chain *) obj)->c ));
-		else
-			return -1;
+		self->c = new Chain(*( ((BPy_Chain *) obj)->c ));
 		
 	} else if( BPy_Id_Check(obj) ) {
-		if( ((BPy_Id *) obj)->id )
-			self->c = new Chain(*( ((BPy_Id *) obj)->id ));
-		else
-			return -1;
+		self->c = new Chain(*( ((BPy_Id *) obj)->id ));
 			
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
 		return -1;
 	}
 
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_AdjacencyIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_AdjacencyIterator.cpp
index 9b92ac4a3a0..872db712e91 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_AdjacencyIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_AdjacencyIterator.cpp
@@ -130,6 +130,7 @@ int AdjacencyIterator___init__(BPy_AdjacencyIterator *self, PyObject *args )
 		self->a_it = new AdjacencyIterator( ((BPy_ViewVertex *) obj1)->vv, restrictToSelection, restrictToUnvisited );
 			
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument(s)");
 		return -1;
 	}
 
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_ChainingIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_ChainingIterator.cpp
index 05822f4c6fe..efa9503de75 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_ChainingIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_ChainingIterator.cpp
@@ -153,10 +153,8 @@ PyObject *ChainingIterator_init( BPy_ChainingIterator *self ) {
 PyObject *ChainingIterator_traverse( BPy_ChainingIterator *self, PyObject *args ) {
 	PyObject *py_a_it;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_a_it) && BPy_AdjacencyIterator_Check(py_a_it) )) {
-		cout << "ERROR: ChainingIterator_traverse" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &AdjacencyIterator_Type, &py_a_it) ))
+		return NULL;
 	
 	if( ((BPy_AdjacencyIterator *) py_a_it)->a_it )
 		self->c_it->traverse(*( ((BPy_AdjacencyIterator *) py_a_it)->a_it ));
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
index 1b3a37b5518..5c35aa612a6 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
@@ -118,7 +118,7 @@ int Interface0DIterator___init__(BPy_Interface0DIterator *self, PyObject *args )
 {	
 	PyObject *obj = 0;
 
-	if (!( PyArg_ParseTuple(args, "O", &obj) && BPy_Interface0DIterator_Check(obj) ))
+	if (!( PyArg_ParseTuple(args, "O!", &Interface0DIterator_Type, &obj) ))
 	    return -1;
 
 	self->if0D_it = new Interface0DIterator(*( ((BPy_Interface0DIterator *) obj)->if0D_it ));
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_SVertexIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_SVertexIterator.cpp
index e7f0be48d96..f7cca5941b4 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_SVertexIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_SVertexIterator.cpp
@@ -143,6 +143,7 @@ int SVertexIterator___init__(BPy_SVertexIterator *self, PyObject *args )
 							f );
 			
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument(s)");
 		return -1;
 	}
 
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_StrokeVertexIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_StrokeVertexIterator.cpp
index 14356970c93..6492d9a1603 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_StrokeVertexIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_StrokeVertexIterator.cpp
@@ -132,6 +132,7 @@ int StrokeVertexIterator___init__(BPy_StrokeVertexIterator *self, PyObject *args
 		self->sv_it = new StrokeInternal::StrokeVertexIterator(*( ((BPy_StrokeVertexIterator *) obj)->sv_it ));
 	
 	} else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
 		return -1;
 	}
 
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_ViewEdgeIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_ViewEdgeIterator.cpp
index 16e2750f4a7..9b913510e4d 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_ViewEdgeIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_ViewEdgeIterator.cpp
@@ -158,10 +158,8 @@ PyObject *ViewEdgeIterator_getCurrentEdge( BPy_ViewEdgeIterator *self ) {
 PyObject *ViewEdgeIterator_setCurrentEdge( BPy_ViewEdgeIterator *self, PyObject *args ) {
 	PyObject *py_ve;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_ve) && BPy_ViewEdge_Check(py_ve) )) {
-		cout << "ERROR: ViewEdgeIterator_setCurrentEdge" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &ViewEdge_Type, &py_ve) ))
+		return NULL;
 
 	self->ve_it->setCurrentEdge( ((BPy_ViewEdge *) py_ve)->ve );
 		
@@ -179,10 +177,8 @@ PyObject *ViewEdgeIterator_getBegin( BPy_ViewEdgeIterator *self ) {
 PyObject *ViewEdgeIterator_setBegin( BPy_ViewEdgeIterator *self, PyObject *args ) {
 	PyObject *py_ve;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_ve) && BPy_ViewEdge_Check(py_ve) )) {
-		cout << "ERROR: ViewEdgeIterator_setBegin" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &ViewEdge_Type, &py_ve) ))
+		return NULL;
 
 	self->ve_it->setBegin( ((BPy_ViewEdge *) py_ve)->ve );
 		
@@ -196,10 +192,8 @@ PyObject *ViewEdgeIterator_getOrientation( BPy_ViewEdgeIterator *self ) {
 PyObject *ViewEdgeIterator_setOrientation( BPy_ViewEdgeIterator *self, PyObject *args ) {
 	PyObject *py_b;
 
-	if(!( PyArg_ParseTuple(args, "O", &py_b) && PyBool_Check(py_b) )) {
-		cout << "ERROR: ViewEdgeIterator_setOrientation" << endl;
-		Py_RETURN_NONE;
-	}
+	if(!( PyArg_ParseTuple(args, "O!", &PyBool_Type, &py_b) ))
+		return NULL;
 
 	self->ve_it->setOrientation( bool_from_PyBool(py_b) );
 		
diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_orientedViewEdgeIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_orientedViewEdgeIterator.cpp
index 0937e04e3a7..45f6cadeb81 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_orientedViewEdgeIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_orientedViewEdgeIterator.cpp
@@ -118,6 +118,10 @@ int orientedViewEdgeIterator___init__(BPy_orientedViewEdgeIterator *self, PyObje
 		self->ove_it = new ViewVertexInternal::orientedViewEdgeIterator();
 	else if( BPy_orientedViewEdgeIterator_Check(obj) )
 		self->ove_it = new ViewVertexInternal::orientedViewEdgeIterator(*( ((BPy_orientedViewEdgeIterator *) obj)->ove_it ));
+	else {
+		PyErr_SetString(PyExc_TypeError, "invalid argument");
+		return -1;
+	}
 	
 	self->py_it.it = self->ove_it;
 	
diff --git a/source/blender/freestyle/intern/python/StrokeShader/BPy_CalligraphicShader.cpp b/source/blender/freestyle/intern/python/StrokeShader/BPy_CalligraphicShader.cpp
index d20fbeab1ec..e61179eb901 100644
--- a/source/blender/freestyle/intern/python/StrokeShader/BPy_CalligraphicShader.cpp
+++ b/source/blender/freestyle/intern/python/StrokeShader/BPy_CalligraphicShader.cpp
@@ -105,9 +105,12 @@ int CalligraphicShader___init__( BPy_CalligraphicShader* self, PyObject *args)
 	PyObject *obj3 = 0, *obj4 = 0;
 	
 
-	if(!( PyArg_ParseTuple(args, "ddOO", &d1, &d2, &obj3, &obj4) 
-		&& PyList_Check(obj3) && PyList_Size(obj3) > 1 && PyBool_Check(obj4) )) {
-		cout << "ERROR: CalligraphicShader___init__" << endl;		
+	if(!( PyArg_ParseTuple(args, "ddO!O!", &d1, &d2, &PyList_Type, &obj3, &PyBool_Type, &obj4) ))
+		return -1;
+	if( PyList_Size(obj3) != 2 ) {
+		stringstream msg("CalligraphicShader() accepts a list of 2 elements (");
+		msg << PyList_Size(obj3) << " found)";
+		PyErr_SetString(PyExc_TypeError, msg.str().c_str());
 		return -1;
 	}
 
diff --git a/source/blender/freestyle/intern/python/StrokeShader/BPy_ConstantThicknessShader.cpp b/source/blender/freestyle/intern/python/StrokeShader/BPy_ConstantThicknessShader.cpp
index a3440295767..9d20000bffe 100644
--- a/source/blender/freestyle/intern/python/StrokeShader/BPy_ConstantThicknessShader.cpp
+++ b/source/blender/freestyle/intern/python/StrokeShader/BPy_ConstantThicknessShader.cpp
@@ -102,7 +102,7 @@ int ConstantThicknessShader___init__( BPy_ConstantThicknessShader* self, PyObjec
 {
 	float f;
 
-	if(!( PyArg_ParseTuple(args, "|f", &f)  )) {
+	if(!( PyArg_ParseTuple(args, "f", &f)  )) {
 		cout << "ERROR: ConstantThicknessShader___init__" << endl;		
 		return -1;
 	}
diff --git a/source/blender/freestyle/intern/python/StrokeShader/BPy_SpatialNoiseShader.cpp b/source/blender/freestyle/intern/python/StrokeShader/BPy_SpatialNoiseShader.cpp
index f8780b7baee..e938714f559 100644
--- a/source/blender/freestyle/intern/python/StrokeShader/BPy_SpatialNoiseShader.cpp
+++ b/source/blender/freestyle/intern/python/StrokeShader/BPy_SpatialNoiseShader.cpp
@@ -106,8 +106,7 @@ int SpatialNoiseShader___init__( BPy_SpatialNoiseShader* self, PyObject *args)
 	PyObject *obj4 = 0, *obj5 = 0;
 	
 
-	if(!( PyArg_ParseTuple(args, "ffiOO", &f1, &f2, &i3, &obj4, &obj5)
-		&& PyBool_Check(obj4) && PyBool_Check(obj5) )) {
+	if(!( PyArg_ParseTuple(args, "ffiO!O!", &f1, &f2, &i3, &PyBool_Type, &obj4, &PyBool_Type, &obj5) )) {
 		cout << "ERROR: SpatialNoiseShader___init__" << endl;		
 		return -1;
 	}
diff --git a/source/blender/freestyle/intern/python/StrokeShader/BPy_StrokeTextureShader.cpp b/source/blender/freestyle/intern/python/StrokeShader/BPy_StrokeTextureShader.cpp
index 480a5b2d2ff..6fe43bb7c4b 100644
--- a/source/blender/freestyle/intern/python/StrokeShader/BPy_StrokeTextureShader.cpp
+++ b/source/blender/freestyle/intern/python/StrokeShader/BPy_StrokeTextureShader.cpp
@@ -105,13 +105,13 @@ int StrokeTextureShader___init__( BPy_StrokeTextureShader* self, PyObject *args)
 	const char *s1;
 	PyObject *obj2 = 0, *obj3 = 0;
 	
-	if(!( PyArg_ParseTuple(args, "s|OO", &s1, &obj2, &obj3) )) {
+	if(!( PyArg_ParseTuple(args, "s|O!O!", &s1, &MediumType_Type, &obj2, &PyBool_Type, &obj3) )) {
 		cout << "ERROR: StrokeTextureShader___init__" << endl;		
 		return -1;
 	}
 
-	Stroke::MediumType mt = (obj2 && BPy_MediumType_Check(obj2)) ? MediumType_from_BPy_MediumType(obj2) : Stroke::OPAQUE_MEDIUM; 
-	bool b = (obj3 && PyBool_Check(obj3)) ? bool_from_PyBool(obj3) : true;
+	Stroke::MediumType mt = (obj2) ? MediumType_from_BPy_MediumType(obj2) : Stroke::OPAQUE_MEDIUM; 
+	bool b = (obj3) ? bool_from_PyBool(obj3) : true;
 	
 	self->py_ss.ss = new StrokeShaders::StrokeTextureShader(s1,mt,b);
 	return 0;
diff --git a/source/blender/freestyle/intern/python/StrokeShader/BPy_ThicknessVariationPatternShader.cpp b/source/blender/freestyle/intern/python/StrokeShader/BPy_ThicknessVariationPatternShader.cpp
index d7f49b60fa5..1a399b72128 100644
--- a/source/blender/freestyle/intern/python/StrokeShader/BPy_ThicknessVariationPatternShader.cpp
+++ b/source/blender/freestyle/intern/python/StrokeShader/BPy_ThicknessVariationPatternShader.cpp
@@ -105,12 +105,12 @@ int ThicknessVariationPatternShader___init__( BPy_ThicknessVariationPatternShade
 	float f2 = 1.0, f3 = 5.0;
 	PyObject *obj4 = 0;
 
-	if(!( PyArg_ParseTuple(args, "s|ffO", &s1, &f2, &f3, &obj4) )) {
+	if(!( PyArg_ParseTuple(args, "s|ffO!", &s1, &f2, &f3, &PyBool_Type, &obj4) )) {
 		cout << "ERROR: ThicknessVariationPatternShader___init__" << endl;		
 		return -1;
 	}
 
-	bool b = (obj4 && PyBool_Check(obj4)) ? bool_from_PyBool(obj4) : true;
+	bool b = (obj4) ? bool_from_PyBool(obj4) : true;
 	self->py_ss.ss = new StrokeShaders::ThicknessVariationPatternShader(s1, f2, f3, b);
 	return 0;