# Protocolo iterador

Hay dos funciones específicas para trabajar con iteradores.

int PyIter_Check(PyObject *o)
  Part of the Stable ABI since version 3.8.

  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)
  Part of the Stable ABI since version 3.10.

  Return non-zero if the object o provides the `AsyncIterator` protocol, and `0` otherwise. This function always succeeds.

  Added in version 3.10.

PyObject *PyIter_Next(PyObject *o)
  Return value: New reference. Part of the Stable ABI.

  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, returns `NULL` and passes along the exception.

Para escribir un bucle que itera sobre un iterador, el código en C debería verse así:

    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

  El valor de enumeración utilizado para representar diferentes resultados de `PyIter_Send()`.

  Added in version 3.10.

PySendResult PyIter_Send(PyObject *iter, PyObject *arg, PyObject **presult)
  Part of the Stable ABI since version 3.10.

  Envía el valor arg al iterador iter. Retorna:

  - `PYGEN_RETURN` si el iterador regresa. El valor de retorno se retorna a través de presult.

  - `PYGEN_NEXT` si el iterador cede. El valor cedido se retorna a través de presult.

  - `PYGEN_ERROR` si el iterador ha lanzado una excepción. presult se establece en `NULL`.

  Added in version 3.10.