Sequence Protocol — Python documentation

Sequence Protocol

int PySequence_Check(PyObject *o)

Return 1 if the object provides sequence protocol, and 0 otherwise. This function always succeeds.

Py_ssize_t PySequence_Size(PyObject *o)

Py_ssize_t PySequence_Length(PyObject *o)

Returns the number of objects in sequence o on success, and -1 on failure. This is equivalent to the Python expression len(o).

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

PyObject *PySequence_Concat(PyObject *o1, PyObject *o2)

Return the concatenation of o1 and o2 on success, and NULL on failure. This is the equivalent of the Python expression o1 + o2.

PyObject *PySequence_Repeat(PyObject *o, Py_ssize_t count)

Return the result of repeating sequence object o count times, or NULL on failure. This is the equivalent of the Python expression o * count.

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

PyObject *PySequence_InPlaceConcat(PyObject *o1, PyObject *o2)

Return the concatenation of o1 and o2 on success, and NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python expression o1 += o2.

PyObject *PySequence_InPlaceRepeat(PyObject *o, Py_ssize_t count)

Return the result of repeating sequence object o count times, or NULL on failure. The operation is done in-place when o supports it. This is the equivalent of the Python expression o *= count.

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

PyObject *PySequence_GetItem(PyObject *o, Py_ssize_t i)

Return the ith element of o, or NULL on failure. This is the equivalent of the Python expression o[i].

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

PyObject *PySequence_GetSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2)

Return the slice of sequence object o between i1 and i2, or NULL on failure. This is the equivalent of the Python expression o[i1:i2].

Changed in version 2.5: This function used an int type for i1 and i2. This might require changes in your code for properly supporting 64-bit systems.

int PySequence_SetItem(PyObject *o, Py_ssize_t i, PyObject *v)

Assign object v to the ith element of o. Raise an exception and return -1 on failure; return 0 on success. This is the equivalent of the Python statement o[i] = v. This function does not steal a reference to v.

If v is NULL, the element is deleted, however this feature is deprecated in favour of using PySequence_DelItem().

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

int PySequence_DelItem(PyObject *o, Py_ssize_t i)

Delete the ith element of object o. Returns -1 on failure. This is the equivalent of the Python statement del o[i].

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

int PySequence_SetSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2, PyObject *v)

Assign the sequence object v to the slice in sequence object o from i1 to i2. Raise an exception and return -1 on failure; return 0 on success. This is the equivalent of the Python statement o[i1:i2] = v.

If v is NULL, the slice is deleted, however this feature is deprecated in favour of using PySequence_DelSlice().

Changed in version 2.5: This function used an int type for i1 and i2. This might require changes in your code for properly supporting 64-bit systems.

int PySequence_DelSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2)

Delete the slice in sequence object o from i1 to i2. Returns -1 on failure. This is the equivalent of the Python statement del o[i1:i2].

Changed in version 2.5: This function used an int type for i1 and i2. This might require changes in your code for properly supporting 64-bit systems.

Py_ssize_t PySequence_Count(PyObject *o, PyObject *value)

Return the number of occurrences of value in o, that is, return the number of keys for which o[key] == value. On failure, return -1. This is equivalent to the Python expression o.count(value).

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

int PySequence_Contains(PyObject *o, PyObject *value)

Determine if o contains value. If an item in o is equal to value, return 1, otherwise return 0. On error, return -1. This is equivalent to the Python expression value in o.

Py_ssize_t PySequence_Index(PyObject *o, PyObject *value)

Return the first index i for which o[i] == value. On error, return -1. This is equivalent to the Python expression o.index(value).

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 *PySequence_List(PyObject *o)

Return a list object with the same contents as the arbitrary sequence o. The returned list is guaranteed to be new.

PyObject *PySequence_Tuple(PyObject *o)

Return a tuple object with the same contents as the arbitrary sequence o or NULL on failure. If o is a tuple, a new reference will be returned, otherwise a tuple will be constructed with the appropriate contents. This is equivalent to the Python expression tuple(o).

PyObject *PySequence_Fast(PyObject *o, const char *m)

Return the sequence o as a list, unless it is already a tuple or list, in which case o is returned. Use PySequence_Fast_GET_ITEM() to access the members of the result. Returns NULL on failure. If the object is not a sequence, raises TypeError with m as the message text.

PyObject *PySequence_Fast_GET_ITEM(PyObject *o, Py_ssize_t i)

Return the ith element of o, assuming that o was returned by PySequence_Fast(), o is not NULL, and that i is within bounds.

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

PyObject **PySequence_Fast_ITEMS(PyObject *o)

Return the underlying array of PyObject pointers. Assumes that o was returned by PySequence_Fast() and o is not NULL.

Note, if a list gets resized, the reallocation may relocate the items array. So, only use the underlying array pointer in contexts where the sequence cannot change.

New in version 2.4.

PyObject *PySequence_ITEM(PyObject *o, Py_ssize_t i)

Return the ith element of o or NULL on failure. Macro form of PySequence_GetItem() but without checking that PySequence_Check() on o is true and without adjustment for negative indices.

New in version 2.3.

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

Py_ssize_t PySequence_Fast_GET_SIZE(PyObject *o)

Returns the length of o, assuming that o was returned by PySequence_Fast() and that o is not NULL. The size can also be gotten by calling PySequence_Size() on o, but PySequence_Fast_GET_SIZE() is faster because it can assume o is a list or tuple.