Iterator Protocol — Python documentation
From Get docs
Python/docs/3.10/c-api/iter
Iterator Protocol
There are two functions specifically for working with iterators.
- int PyIter_Check(PyObject *o)
- Return non-zero if the object o can be safely passed to PyIter_Next(), and
0
otherwise. This function always succeeds.
- int PyAIter_Check(PyObject *o)
Returns non-zero if the object ‘obj’ provides
AsyncIterator
protocols, and0
otherwise. This function always succeeds.New in version 3.10.
- Return the next value from the iterator o. The object must be an iterator according to PyIter_Check() (it is up to the caller to check this). If there are no remaining values, returns
NULL
with no exception set. If an error occurs while retrieving the item, returnsNULL
and passes along the exception.
To write a loop which iterates over an iterator, the C code should look something like this:
PyObject *iterator = PyObject_GetIter(obj);
PyObject *item;
if (iterator == NULL) {
/* propagate error */
}
while ((item = PyIter_Next(iterator))) {
/* do something with item */
...
/* release reference when done */
Py_DECREF(item);
}
Py_DECREF(iterator);
if (PyErr_Occurred()) {
/* propagate error */
}
else {
/* continue doing useful work */
}
- type PySendResult
The enum value used to represent different results of PyIter_Send().
New in version 3.10.
- PySendResult PyIter_Send(PyObject *iter, PyObject *arg, PyObject **presult)
Sends the arg value into the iterator iter. Returns:
PYGEN_RETURN
if iterator returns. Return value is returned via presult.PYGEN_NEXT
if iterator yields. Yielded value is returned via presult.PYGEN_ERROR
if iterator has raised and exception. presult is set toNULL
.
New in version 3.10.