Slice Objects¶
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PyTypeObject
PySlice_Type¶ The type object for slice objects. This is the same as
slicein the Python layer.
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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 theNonewill be used for the corresponding attribute. ReturnNULLif the new object could not be allocated.
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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
0on success and-1on error with no exception set (unless one of the indices was notNoneand failed to be converted to an integer, in which case-1is returned with an exception set).You probably do not want to use this function.
Changed in version 3.2: The parameter type for the slice parameter was
PySliceObject*before.
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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
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
0on success and-1on error with exception set.Note
This function is considered not safe for resizable sequences. Its invocation should be replaced by a combination of
PySlice_Unpack()andPySlice_AdjustIndices()whereif (PySlice_GetIndicesEx(slice, length, &start, &stop, &step, &slicelength) < 0) { // return error }
is replaced by
if (PySlice_Unpack(slice, &start, &stop, &step) < 0) { // return error } slicelength = PySlice_AdjustIndices(length, &start, &stop, step);
Changed in version 3.2: The parameter type for the slice parameter was
PySliceObject*before.Changed in version 3.6.1: If
Py_LIMITED_APIis not set or set to the value between0x03050400and0x03060000(not including) or0x03060100or higherPySlice_GetIndicesEx()is implemented as a macro usingPySlice_Unpack()andPySlice_AdjustIndices(). Arguments start, stop and step are evaluated more than once.Deprecated since version 3.6.1: If
Py_LIMITED_APIis set to the value less than0x03050400or between0x03060000and0x03060100(not including)PySlice_GetIndicesEx()is a deprecated function.
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int
PySlice_Unpack(PyObject *slice, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step)¶ Extract the start, stop and step data members from a slice object as C integers. Silently reduce values larger than
PY_SSIZE_T_MAXtoPY_SSIZE_T_MAX, silently boost the start and stop values less thanPY_SSIZE_T_MINtoPY_SSIZE_T_MIN, and silently boost the step values less than-PY_SSIZE_T_MAXto-PY_SSIZE_T_MAX.Return
-1on error,0on success.New in version 3.6.1.
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Py_ssize_t
PySlice_AdjustIndices(Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t step)¶ Adjust start/end slice indices assuming a sequence of the specified length. Out of bounds indices are clipped in a manner consistent with the handling of normal slices.
Return the length of the slice. Always successful. Doesn’t call Python code.
New in version 3.6.1.