切片物件
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PyTypeObject PySlice_Type
    * 為 穩定 ABI 的一部分.*

   The type object for slice objects.  This is the same as "slice" in
   the Python layer.

int PySlice_Check(PyObject *ob)

   Return true if *ob* is a slice object; *ob* must not be "NULL".
   This function always succeeds.

PyObject *PySlice_New(PyObject *start, PyObject *stop, PyObject *step)
    *回傳值：新的參照。** 為 穩定 ABI 的一部分.*

   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" with an exception set if the new object could not be
   allocated.

int PySlice_GetIndices(PyObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step)
    * 為 穩定 ABI 的一部分.*

   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.

   在 3.2 版的變更: The parameter type for the *slice* parameter was
   "PySliceObject*" before.

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)
    * 為 穩定 ABI 的一部分.*

   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.

   成功時回傳 "0" ，在失敗時回傳 "-1" 並設定例外。

   備註:

     This function is considered not safe for resizable sequences. Its
     invocation should be replaced by a combination of
     "PySlice_Unpack()" and "PySlice_AdjustIndices()" where

        if (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);

   在 3.2 版的變更: The parameter type for the *slice* parameter was
   "PySliceObject*" before.

   在 3.6.1 版的變更: If "Py_LIMITED_API" is not set or set to the
   value between "0x03050400" and "0x03060000" (not including) or
   "0x03060100" or higher "PySlice_GetIndicesEx()" is implemented as a
   macro using "PySlice_Unpack()" and "PySlice_AdjustIndices()".
   Arguments *start*, *stop* and *step* are evaluated more than once.

   在 3.6.1 版之後被棄用: If "Py_LIMITED_API" is set to the value less
   than "0x03050400" or between "0x03060000" and "0x03060100" (not
   including) "PySlice_GetIndicesEx()" is a deprecated function.

int PySlice_Unpack(PyObject *slice, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step)
    * 為 穩定 ABI 的一部分 自 3.7 版本開始.*

   Extract the start, stop and step data members from a slice object
   as C integers.  Silently reduce values larger than "PY_SSIZE_T_MAX"
   to "PY_SSIZE_T_MAX", silently boost the start and stop values less
   than "PY_SSIZE_T_MIN" to "PY_SSIZE_T_MIN", and silently boost the
   step values less than "-PY_SSIZE_T_MAX" to "-PY_SSIZE_T_MAX".

   成功時回傳 "0"，在失敗時回傳 "-1" 並設定例外。

   在 3.6.1 版被加入.

Py_ssize_t PySlice_AdjustIndices(Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t step)
    * 為 穩定 ABI 的一部分 自 3.7 版本開始.*

   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.

   在 3.6.1 版被加入.


Ellipsis Object
===============

PyObject *Py_Ellipsis

   The Python "Ellipsis" object.  This object has no methods.  Like
   "Py_None", it is an *immortal* singleton object.

   在 3.12 版的變更: "Py_Ellipsis" 為不滅的 (immortal)。
