cpython/Doc/c-api/iterator.rst
Antonio Cuni 315fc52db1
bpo-42528: Improve the docs of most Py*_Check{,Exact} API calls (GH-23602)
I think that none of these API calls can fail, but only few of them are
documented as such. Add the sentence "This function always succeeds" (which is
the same already used e.g. by PyNumber_Check) to all of them.
2021-01-06 12:38:26 +01:00

53 lines
1.7 KiB
ReStructuredText

.. highlight:: c
.. _iterator-objects:
Iterator Objects
----------------
Python provides two general-purpose iterator objects. The first, a sequence
iterator, works with an arbitrary sequence supporting the :meth:`__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.
.. c:var:: PyTypeObject PySeqIter_Type
Type object for iterator objects returned by :c:func:`PySeqIter_New` and the
one-argument form of the :func:`iter` built-in function for built-in sequence
types.
.. c:function:: int PySeqIter_Check(op)
Return true if the type of *op* is :c:data:`PySeqIter_Type`. This function
always succeeds.
.. c:function:: PyObject* PySeqIter_New(PyObject *seq)
Return an iterator that works with a general sequence object, *seq*. The
iteration ends when the sequence raises :exc:`IndexError` for the subscripting
operation.
.. c:var:: PyTypeObject PyCallIter_Type
Type object for iterator objects returned by :c:func:`PyCallIter_New` and the
two-argument form of the :func:`iter` built-in function.
.. c:function:: int PyCallIter_Check(op)
Return true if the type of *op* is :c:data:`PyCallIter_Type`. This
function always succeeds.
.. c:function:: PyObject* PyCallIter_New(PyObject *callable, PyObject *sentinel)
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.