Python 3.6.5 Documentation >  List Objects

List Objects
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PyListObject

This subtype of "PyObject" represents a Python list object.

PyTypeObject PyList_Type

This instance of "PyTypeObject" represents the Python list type.
This is the same object as "list" in the Python layer.

int PyList_Check(PyObject *p)

Return true if *p* is a list object or an instance of a subtype of
the list type.

int PyList_CheckExact(PyObject *p)

Return true if *p* is a list object, but not an instance of a
subtype of the list type.

PyObject* PyList_New(Py_ssize_t len)
*Return value: New reference.*

Return a new list of length *len* on success, or *NULL* on failure.

Note: If *len* is greater than zero, the returned list object’s
items are set to "NULL". Thus you cannot use abstract API
functions such as "PySequence_SetItem()" or expose the object to
Python code before setting all items to a real object with
"PyList_SetItem()".

Py_ssize_t PyList_Size(PyObject *list)

Return the length of the list object in *list*; this is equivalent
to "len(list)" on a list object.

Py_ssize_t PyList_GET_SIZE(PyObject *list)

Macro form of "PyList_Size()" without error checking.

PyObject* PyList_GetItem(PyObject *list, Py_ssize_t index)
*Return value: Borrowed reference.*

Return the object at position *index* in the list pointed to by
*list*. The position must be positive, indexing from the end of
the list is not supported. If *index* is out of bounds, return
*NULL* and set an "IndexError" exception.

PyObject* PyList_GET_ITEM(PyObject *list, Py_ssize_t i)
*Return value: Borrowed reference.*

Macro form of "PyList_GetItem()" without error checking.

int PyList_SetItem(PyObject *list, Py_ssize_t index, PyObject *item)

Set the item at index *index* in list to *item*. Return "0" on
success or "-1" on failure.

Note: This function “steals” a reference to *item* and discards a
reference to an item already in the list at the affected
position.

void PyList_SET_ITEM(PyObject *list, Py_ssize_t i, PyObject *o)

Macro form of "PyList_SetItem()" without error checking. This is
normally only used to fill in new lists where there is no previous
content.

Note: This macro “steals” a reference to *item*, and, unlike
"PyList_SetItem()", does *not* discard a reference to any item
that is being replaced; any reference in *list* at position *i*
will be leaked.

int PyList_Insert(PyObject *list, Py_ssize_t index, PyObject *item)

Insert the item *item* into list *list* in front of index *index*.
Return "0" if successful; return "-1" and set an exception if
unsuccessful. Analogous to "list.insert(index, item)".

int PyList_Append(PyObject *list, PyObject *item)

Append the object *item* at the end of list *list*. Return "0" if
successful; return "-1" and set an exception if unsuccessful.
Analogous to "list.append(item)".

PyObject* PyList_GetSlice(PyObject *list, Py_ssize_t low, Py_ssize_t high)
*Return value: New reference.*

Return a list of the objects in *list* containing the objects
*between* *low* and *high*. Return *NULL* and set an exception if
unsuccessful. Analogous to "list[low:high]". Negative indices, as
when slicing from Python, are not supported.

int PyList_SetSlice(PyObject *list, Py_ssize_t low, Py_ssize_t high, PyObject *itemlist)

Set the slice of *list* between *low* and *high* to the contents of
*itemlist*. Analogous to "list[low:high] = itemlist". The
*itemlist* may be *NULL*, indicating the assignment of an empty
list (slice deletion). Return "0" on success, "-1" on failure.
Negative indices, as when slicing from Python, are not supported.

int PyList_Sort(PyObject *list)

Sort the items of *list* in place. Return "0" on success, "-1" on
failure. This is equivalent to "list.sort()".

int PyList_Reverse(PyObject *list)

Reverse the items of *list* in place. Return "0" on success, "-1"
on failure. This is the equivalent of "list.reverse()".

PyObject* PyList_AsTuple(PyObject *list)
*Return value: New reference.*

Return a new tuple object containing the contents of *list*;
equivalent to "tuple(list)".

int PyList_ClearFreeList()

Clear the free list. Return the total number of freed items.

New in version 3.3.