Hi list
I'm trying to implement a new type in a C extension and it must support some binary operators, like &, |, ^, << and >>. With &, | and ^, the method must receive another object of the same type, perform the operation with an attribute of both, create a new object with the result as the attribute and return it. Everything works perfectly with &, | and ^, but with << and >> I need to, pass an integer as argument, not an object of the same type. The method should receive an integer, perform the shift with the attribute, create the new object and return it. The problem is that it only works with another object of the same type. It's strange because obj.__lshift__ returns the method; when I call obj.__lshift__(a) or obj << a, when a is an object of the same type, the call suceeds (but the object returned has the wrong value, of course), but with obj.__lshift__(i) where i is an integer, the call returns NotImplemented and with obj << i it raises TypeError: unsupported operand types for <<. I searched the Objects/ directory in the interpreter source code, but could not find any solution for this. Seems like it does some kind of type-checking somewhere when using these binary operators. Do I need to implement the __coerce__ method or use some wrapper with the method function ? Here is the relevant piece of my source code: The __lshift__ method: /* Pin.__lshift__() */ static PyObject * Pin_oplshift(PinObject *self, PyObject *args){ PinObject *result; int shift; if (!PyArg_ParseTuple(args, "i", &shift)) return NULL; result = PyObject_NEW(PinObject, &PinType); result->pin = self->pin << shift; Py_INCREF(result); return (PyObject *) result; }; The part of the PyNumberMethods struct: /* Pin number methods */ static PyNumberMethods PinAsNumber[] = { ... (inquiry)Pin_nonzero, /*nb_nonzero*/ 0, /*nb_invert*/ (binaryfunc)Pin_oplshift, /*nb_lshift*/ (binaryfunc)Pin_oprshift, /*nb_rshift*/ (binaryfunc)Pin_and, /*nb_and*/ (binaryfunc)Pin_xor, /*nb_xor*/ (binaryfunc)Pin_or, /*nb_or*/ 0, /*nb_coerce*/ ... }; Thanks for any help... -- Pedro Werneck -- http://mail.python.org/mailman/listinfo/python-list