1#ifndef Py_CPYTHON_LISTOBJECT_H
2# error "this header file must not be included directly"
3#endif
4
5typedef struct {
6 PyObject_VAR_HEAD
7 /* Vector of pointers to list elements. list[0] is ob_item[0], etc. */
8 PyObject **ob_item;
9
10 /* ob_item contains space for 'allocated' elements. The number
11 * currently in use is ob_size.
12 * Invariants:
13 * 0 <= ob_size <= allocated
14 * len(list) == ob_size
15 * ob_item == NULL implies ob_size == allocated == 0
16 * list.sort() temporarily sets allocated to -1 to detect mutations.
17 *
18 * Items must normally not be NULL, except during construction when
19 * the list is not yet visible outside the function that builds it.
20 */
21 Py_ssize_t allocated;
22} PyListObject;
23
24PyAPI_FUNC(PyObject *) _PyList_Extend(PyListObject *, PyObject *);
25PyAPI_FUNC(void) _PyList_DebugMallocStats(FILE *out);
26
27/* Macro, trading safety for speed */
28
29/* Cast argument to PyListObject* type. */
30#define _PyList_CAST(op) (assert(PyList_Check(op)), (PyListObject *)(op))
31
32#define PyList_GET_ITEM(op, i) (_PyList_CAST(op)->ob_item[i])
33#define PyList_SET_ITEM(op, i, v) ((void)(_PyList_CAST(op)->ob_item[i] = (v)))
34#define PyList_GET_SIZE(op) Py_SIZE(_PyList_CAST(op))
35

source code of include/python3.10/cpython/listobject.h