Python.Runtime.Exceptions.SetArgsAndCause C# (CSharp) Method

        internal static void SetArgsAndCause(IntPtr ob)
        {
            var e = ExceptionClassObject.ToException(ob);
            if (e == null)
                return;

            IntPtr args;
            if (!string.IsNullOrEmpty(e.Message))
            {
                args = Runtime.PyTuple_New(1);
                var msg = Runtime.PyUnicode_FromString(e.Message);
                Runtime.PyTuple_SetItem(args, 0, msg);
            }
            else
            {
                args = Runtime.PyTuple_New(0);
            }

            Marshal.WriteIntPtr(ob, ExceptionOffset.args, args);

            #if PYTHON3
            if (e.InnerException != null)
            {
                IntPtr cause = CLRObject.GetInstHandle(e.InnerException);
                Marshal.WriteIntPtr(ob, ExceptionOffset.cause, cause);
            }
            #endif
        }

        internal CLRObject(object ob, IntPtr tp)
        {
            IntPtr py = Runtime.PyType_GenericAlloc(tp, 0);

            long flags = Util.ReadCLong(tp, TypeOffset.tp_flags);

            if ((flags & TypeFlags.Subclass) != 0)
            {
                IntPtr dict = Marshal.ReadIntPtr(py, ObjectOffset.TypeDictOffset(tp));
                if (dict == IntPtr.Zero)
                {
                    dict = Runtime.PyDict_New();
                    Marshal.WriteIntPtr(py, ObjectOffset.TypeDictOffset(tp), dict);
                }
            }

            GCHandle gc = GCHandle.Alloc(this);

            Marshal.WriteIntPtr(py, ObjectOffset.magic(tp), (IntPtr)gc);
            tpHandle = tp;
            pyHandle = py;
            gcHandle = gc;
            inst     = ob;

            // for performance before calling SetArgsAndCause() lets check if we are an exception
            if (inst is Exception)
            {
                // Fix the BaseException args (and __cause__ in case of Python 3)
                // slot if wrapping a CLR exception
                Exceptions.SetArgsAndCause(py);
            }
        }