# Protocole d'itération

Il existe deux fonctions dédiées à l'interaction avec les itérateurs.

int `PyIter_Check`(PyObject *o)

  Return true if the object o supports the iterator protocol. This function always succeeds.

PyObject* `PyIter_Next`(PyObject *o)
  Return value: New reference.

  Return the next value from the iteration o. The object must be an iterator (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.

Pour écrire une boucle itérant un itérateur, le code C devrait ressembler à :

    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 */
    }