List Objects

This subtype of PyObject represents a Python list object.

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

Return true if p is a list object or an instance of a subtype of the list type. This function always succeeds.

Return true if p is a list object, but not an instance of a subtype of the list type. This function always succeeds.

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 or PyList_SET_ITEM(). The following APIs are safe APIs before the list is fully initialized: PyList_SetItem() and PyList_SET_ITEM().

pair: built-in function; len

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

Similar to PyList_Size, but without error checking.

Return the object at position index in the list pointed to by list. The position must be non-negative; indexing from the end of the list is not supported. If index is out of bounds (<0 or >=len(list)), return NULL and set an IndexError exception.

3.13

Like PyList_GetItemRef, but returns a borrowed reference instead of a strong reference.

[!NOTE] In the free-threaded build, the returned borrowed reference may become invalid if another thread modifies the list concurrently. Prefer PyList_GetItemRef, which returns a strong reference.

Similar to PyList_GetItem, but without error checking.

[!NOTE] In the free-threaded build, the returned borrowed reference may become invalid if another thread modifies the list concurrently. Prefer PyList_GetItemRef, which returns a strong reference.

Set the item at index index in list to item. Return 0 on success. If index is out of bounds, return -1 and set an IndexError exception.

[!NOTE] This function "steals <steal>" a reference to item, even on error. On success, it discards a reference to an item already in the list at the affected position (unless it was NULL).

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

Bounds checking is performed as an assertion if Python is built in debug mode <debug-build> or with assertions <--with-assertions>.

[!NOTE] This macro "steals <steal>" 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.

[!NOTE] In the free-threaded build, this macro has no internal synchronization. It is normally only used to fill in new lists where no other thread has a reference to the list. If the list may be shared, use PyList_SetItem instead, which uses a per-object lock.

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).

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).

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]. Indexing from the end of the list is not supported.

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. Indexing from the end of the list is not supported.

[!NOTE] In the free-threaded build, when itemlist is a list, both list and itemlist are locked for the duration of the operation. For other iterables (or NULL), only list is locked.

Extend list with the contents of iterable. This is the same as PyList_SetSlice(list, PY_SSIZE_T_MAX, PY_SSIZE_T_MAX, iterable) and analogous to list.extend(iterable) or list += iterable.

Raise an exception and return -1 if list is not a list object. Return 0 on success.

3.13

[!NOTE] In the free-threaded build, when iterable is a list, set, dict, or dict view, both list and iterable (or its underlying dict) are locked for the duration of the operation. For other iterables, only list is locked; iterable may be concurrently modified by another thread.

Remove all items from list. This is the same as PyList_SetSlice(list, 0, PY_SSIZE_T_MAX, NULL) and analogous to list.clear() or del list[:].

Raise an exception and return -1 if list is not a list object. Return 0 on success.

3.13

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

[!NOTE] In the free-threaded build, element comparison via ~object.__lt__ can execute arbitrary Python code, during which the per-object lock may be temporarily released. For built-in types (str, int, float), the lock is not released during comparison.

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

pair: built-in function; tuple

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