List Objects

Working with Python list type

Overview

Lists are mutable sequences of Python objects with O(1) indexing and append.

Creating Lists

PyObject* PyList_New(Py_ssize_t len)

Create new list with len items (initially NULL).

Example:

PyObject *list = PyList_New(3);
PyList_SetItem(list, 0, PyLong_FromLong(1));  // Steals ref
PyList_SetItem(list, 1, PyLong_FromLong(2));
PyList_SetItem(list, 2, PyLong_FromLong(3));
return list;

Accessing Items

PyObject* PyList_GetItem(PyObject *list, Py_ssize_t index)  // Borrowed!
Py_ssize_t PyList_Size(PyObject *list)

PyList_GetItem returns borrowed reference - don’t Py_DECREF!

Modifying Lists

int PyList_SetItem(PyObject *list, Py_ssize_t index, PyObject *item)  // Steals!
int PyList_Append(PyObject *list, PyObject *item)  // Doesn't steal
int PyList_Insert(PyObject *list, Py_ssize_t index, PyObject *item)

See Also

• Object Protocol
• Reference Counting