jggramlich at yahoo.com (Joshua Gramlich) writes: > if(!PyArg_ParseTuple(args, "!O", &list)) [...] > TypeError: argument 1 must be impossible<bad format char>, not tuple The format string is in error. "O" means "arbitrary object". "O!" means "object of required type" (which you have to provide to ParseTuple as well), "!O" is meaningless. Regards, Martin