# Iterator Objects

Python provides two general-purpose iterator objects. The first, a sequence iterator, works with an arbitrary sequence supporting the `__getitem__()` method. The second works with a callable object and a sentinel value, calling the callable for each item in the sequence, and ending the iteration when the sentinel value is returned.

PyTypeObject `PySeqIter_Type`
  Part of the Stable ABI.

  Type object for iterator objects returned by `PySeqIter_New()` and the one-argument form of the `iter()` built-in function for built-in sequence types.

int `PySeqIter_Check`(op)

  Return true if the type of op is `PySeqIter_Type`. This function always succeeds.

PyObject *`PySeqIter_New`(PyObject *seq)
  Return value: New reference. Part of the Stable ABI.

  Return an iterator that works with a general sequence object, seq. The iteration ends when the sequence raises `IndexError` for the subscripting operation.

PyTypeObject `PyCallIter_Type`
  Part of the Stable ABI.

  Type object for iterator objects returned by `PyCallIter_New()` and the two-argument form of the `iter()` built-in function.

int `PyCallIter_Check`(op)

  Return true if the type of op is `PyCallIter_Type`. This function always succeeds.

PyObject *`PyCallIter_New`(PyObject *callable, PyObject *sentinel)
  Return value: New reference. Part of the Stable ABI.

  Return a new iterator. The first parameter, callable, can be any Python callable object that can be called with no parameters; each call to it should return the next item in the iteration. When callable returns a value equal to sentinel, the iteration will be terminated.