.. highlightlang:: c

.. _slice-objects:

Slice Objects
-------------


.. c:var:: PyTypeObject PySlice_Type

   The type object for slice objects.  This is the same as :class:`slice` in the
   Python layer.


.. c:function:: int PySlice_Check(PyObject *ob)

   Return true if *ob* is a slice object; *ob* must not be *NULL*.


.. c:function:: PyObject* PySlice_New(PyObject *start, PyObject *stop, PyObject *step)

   Return a new slice object with the given values.  The *start*, *stop*, and
   *step* parameters are used as the values of the slice object attributes of
   the same names.  Any of the values may be *NULL*, in which case the
   ``None`` will be used for the corresponding attribute.  Return *NULL* if
   the new object could not be allocated.


.. c:function:: int PySlice_GetIndices(PyObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step)

   Retrieve the start, stop and step indices from the slice object *slice*,
   assuming a sequence of length *length*. Treats indices greater than
   *length* as errors.

   Returns ``0`` on success and ``-1`` on error with no exception set (unless one of
   the indices was not :const:`None` and failed to be converted to an integer,
   in which case ``-1`` is returned with an exception set).

   You probably do not want to use this function.

   .. versionchanged:: 3.2
      The parameter type for the *slice* parameter was ``PySliceObject*``
      before.


.. c:function:: int PySlice_GetIndicesEx(PyObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step, Py_ssize_t *slicelength)

   Usable replacement for :c:func:`PySlice_GetIndices`.  Retrieve the start,
   stop, and step indices from the slice object *slice* assuming a sequence of
   length *length*, and store the length of the slice in *slicelength*.  Out
   of bounds indices are clipped in a manner consistent with the handling of
   normal slices.

   Returns ``0`` on success and ``-1`` on error with exception set.

   .. versionchanged:: 3.2
      The parameter type for the *slice* parameter was ``PySliceObject*``
      before.


Ellipsis Object
---------------


.. c:var:: PyObject *Py_Ellipsis

   The Python ``Ellipsis`` object.  This object has no methods.  It needs to be
   treated just like any other object with respect to reference counts.  Like
   :c:data:`Py_None` it is a singleton object.