15.20 处理C语言中的可迭代对象

## 问题 You want to write C extension code that consumes items from any iterable object suchas a list, tuple, file, or generator. ## 解决方案 Here is a sample C extension function that shows how to consume the items on aniterable: static PyObject [*](#)py_consume_iterable(PyObject [*](#)self, PyObject [*](#)args) { PyObject [*](#)obj;PyObject [*](#)iter;PyObject [*](#)item; if (!PyArg_ParseTuple(args, “O”, &obj)) {return NULL; }if ((iter = PyObject_GetIter(obj)) == NULL) { > return NULL; }while ((item = PyIter_Next(iter)) != NULL) { > /* Use item [*](#)/...Py_DECREF(item); } Py_DECREF(iter);return Py_BuildValue(“”); } ## 讨论 The code in this recipe mirrors similar code in Python. The PyObject_GetIter() callis the same as calling iter() to get an iterator. The PyIter_Next() function invokesthe next method on the iterator returning the next item or NULL if there are no moreitems. Make sure you’re careful with memory management—Py_DECREF() needs to becalled on both the produced items and the iterator object itself to avoid leaking memory.