7.5.8 Slice Objects

Python 2.5

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7.5.8 Slice Objects

PyTypeObject PySlice_Type: The type object for slice objects. This is the same as slice and types.SliceType.

int PySlice_Check( PyObject *ob): Return true if ob is a slice object; ob must not be NULL.

PyObject* PySlice_New( PyObject *start, PyObject *stop, PyObject *step): Return value: New reference.
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.

int PySlice_GetIndices( PySliceObject *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 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. If you want to use slice objects in versions of Python prior to 2.3, you would probably do well to incorporate the source of PySlice_GetIndicesEx, suitably renamed, in the source of your extension.

int PySlice_GetIndicesEx( PySliceObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step, Py_ssize_t *slicelength)

Usable replacement for 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.

New in version 2.3.

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