Tuple Objects — Python 2.7.18 documentation

This document is for an old version of Python that is no longer supported. You should upgrade and read the Python documentation for the current stable release.

# Tuple Objects

`PyTupleObject`

  This subtype of `PyObject` represents a Python tuple object.

PyTypeObject `PyTuple_Type`

  This instance of `PyTypeObject` represents the Python tuple type; it is the same object as `tuple` and `types.TupleType` in the Python layer..

int `PyTuple_Check`(PyObject *p)

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

  Changed in version 2.2: Allowed subtypes to be accepted.

int `PyTuple_CheckExact`(PyObject *p)

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

  New in version 2.2.

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

  Return a new tuple object of size len, or NULL on failure.

  Changed in version 2.5: This function used an `int` type for len. This might require changes in your code for properly supporting 64-bit systems.

PyObject* `PyTuple_Pack`(Py_ssize_t n, ...)
  Return value: New reference.

  Return a new tuple object of size n, or NULL on failure. The tuple values are initialized to the subsequent n C arguments pointing to Python objects. `PyTuple_Pack(2, a, b)` is equivalent to `Py_BuildValue("(OO)", a, b)`.

  New in version 2.4.

  Changed in version 2.5: This function used an `int` type for n. This might require changes in your code for properly supporting 64-bit systems.

Py_ssize_t `PyTuple_Size`(PyObject *p)

  Take a pointer to a tuple object, and return the size of that tuple.

  Changed in version 2.5: This function returned an `int` type. This might require changes in your code for properly supporting 64-bit systems.

Py_ssize_t `PyTuple_GET_SIZE`(PyObject *p)

  Return the size of the tuple p, which must be non-NULL and point to a tuple; no error checking is performed.

  Changed in version 2.5: This function returned an `int` type. This might require changes in your code for properly supporting 64-bit systems.

PyObject* `PyTuple_GetItem`(PyObject *p, Py_ssize_t pos)
  Return value: Borrowed reference.

  Return the object at position pos in the tuple pointed to by p. If pos is out of bounds, return NULL and set an `IndexError` exception.

  Changed in version 2.5: This function used an `int` type for pos. This might require changes in your code for properly supporting 64-bit systems.

PyObject* `PyTuple_GET_ITEM`(PyObject *p, Py_ssize_t pos)
  Return value: Borrowed reference.

  Like `PyTuple_GetItem()`, but does no checking of its arguments.

  Changed in version 2.5: This function used an `int` type for pos. This might require changes in your code for properly supporting 64-bit systems.

PyObject* `PyTuple_GetSlice`(PyObject *p, Py_ssize_t low, Py_ssize_t high)
  Return value: New reference.

  Return the slice of the tuple pointed to by p between low and high, or NULL on failure. This is the equivalent of the Python expression `p[low:high]`. Indexing from the end of the list is not supported.

  Changed in version 2.5: This function used an `int` type for low and high. This might require changes in your code for properly supporting 64-bit systems.

int `PyTuple_SetItem`(PyObject *p, Py_ssize_t pos, PyObject *o)

  Insert a reference to object o at position pos of the tuple pointed to by p. Return `0` on success. If pos is out of bounds, return `-1` and set an `IndexError` exception.

  Note

  This function “steals” a reference to o and discards a reference to an item already in the tuple at the affected position.

  Changed in version 2.5: This function used an `int` type for pos. This might require changes in your code for properly supporting 64-bit systems.

void `PyTuple_SET_ITEM`(PyObject *p, Py_ssize_t pos, PyObject *o)

  Like `PyTuple_SetItem()`, but does no error checking, and should only be used to fill in brand new tuples.

  Note

  This macro “steals” a reference to o, and, unlike `PyTuple_SetItem()`, does not discard a reference to any item that is being replaced; any reference in the tuple at position pos will be leaked.

  Changed in version 2.5: This function used an `int` type for pos. This might require changes in your code for properly supporting 64-bit systems.

int `_PyTuple_Resize`(PyObject **p, Py_ssize_t newsize)

  Can be used to resize a tuple. newsize will be the new length of the tuple. Because tuples are supposed to be immutable, this should only be used if there is only one reference to the object. Do not use this if the tuple may already be known to some other part of the code. The tuple will always grow or shrink at the end. Think of this as destroying the old tuple and creating a new one, only more efficiently. Returns `0` on success. Client code should never assume that the resulting value of `*p` will be the same as before calling this function. If the object referenced by `*p` is replaced, the original `*p` is destroyed. On failure, returns `-1` and sets `*p` to NULL, and raises `MemoryError` or `SystemError`.

  Changed in version 2.2: Removed unused third parameter, last_is_sticky.

  Changed in version 2.5: This function used an `int` type for newsize. This might require changes in your code for properly supporting 64-bit systems.

int `PyTuple_ClearFreeList`()

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

  New in version 2.6.