diff --git a/python/pyextension_utils.c b/python/pyextension_utils.c
new file mode 100644
index 0000000..e9cf369
--- /dev/null
+++ b/python/pyextension_utils.c
@@ -0,0 +1,138 @@
+/*
+pyextension_utils.c : C extension utilities for Python
+
+Copyright (C) 2014 Simon D. Levy
+
+This code is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as 
+published by the Free Software Foundation, either version 3 of the 
+License, or (at your option) any later version.
+
+This code is distributed in the hope that it will be useful,     
+but WITHOUT ANY WARRANTY without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License 
+along with this code.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <Python.h>
+
+static void raise_argument_exception(const char * classname, const char *  methodname, const char * details)
+{
+    char errmsg[1000];
+    sprintf(errmsg, "Wrong/insufficient arguments passed to %s.%s()%s %s", 
+        classname, methodname, 
+        details ? ":" : "", details ? details : "");
+    PyErr_SetString(PyExc_TypeError, errmsg);
+    
+}
+
+PyObject * null_on_raise_argument_exception_with_details(const char * classname, const char *  methodname, const char * details)
+{
+    raise_argument_exception(classname, methodname, details);
+    return NULL;
+}
+
+PyObject *null_on_raise_argument_exception(const char * classname, const char *  methodname)
+{
+    return null_on_raise_argument_exception_with_details(classname, methodname, NULL);
+}
+
+int error_on_raise_argument_exception_with_details(const char * classname, const char *  methodname, const char * details)
+{
+    raise_argument_exception(classname, methodname, details);
+    return -1;
+}
+
+int error_on_raise_argument_exception(const char * classname)
+{
+    return error_on_raise_argument_exception_with_details(classname, "__init__", NULL);
+}
+
+int type_is_ready(PyTypeObject * type)
+{
+    return (PyType_Ready(type) >= 0);
+}
+
+
+void add_class(PyObject * module, PyTypeObject * type, const char * classname)
+{
+    Py_INCREF(type);
+    PyModule_AddObject(module, classname, (PyObject *)type);
+    
+}
+
+int double_from_tuple(PyObject * tup,   int pos,   double * val)
+{
+    PyObject * py_val = PyTuple_GetItem(tup, pos);
+    
+    if (py_val)
+    {
+        *val = PyFloat_AsDouble(py_val);
+        return PyErr_Occurred() ? 0 : 1;         
+    }
+    
+    return 0;
+}
+
+
+int
+double_from_obj(
+    PyObject * obj,
+    const char * name,
+    double * val)
+{
+    PyObject * attr = PyObject_GetAttrString(obj, name);
+    
+    if (!attr)
+    {
+        return 0;
+    }
+    
+    *val = PyFloat_AsDouble(attr);
+    
+    return 1;
+}
+
+
+int
+int_from_obj(
+    PyObject * obj,
+    const char * name,
+    int * val)
+{    
+    PyObject * attr = PyObject_GetAttrString(obj, name);
+    
+    if (!attr)
+    {
+        return 0;
+    }
+    
+    *val = PyLong_AsLong(attr);
+    
+    return 1;
+}
+
+
+int 
+error_on_check_argument_type(
+    PyObject * obj, 
+    PyTypeObject * typ, 
+    int pos,
+    const char * typname, 
+    const char * classname,
+    const char *methodname)
+{
+    
+    if (!PyObject_TypeCheck(obj, typ))
+    {
+        char details[200];
+        sprintf(details, "argument %d is not of type %s", pos+1, typname);
+        raise_argument_exception(classname, methodname, details);
+        return -1;
+    }
+    
+    return 0;
+}