New in version 2.5.
This section details the public API for set
and frozenset
objects. Any functionality not listed below is best accessed using the either
the abstract object protocol (including PyObject_CallMethod()
,
PyObject_RichCompareBool()
, PyObject_Hash()
,
PyObject_Repr()
, PyObject_IsTrue()
, PyObject_Print()
, and
PyObject_GetIter()
) or the abstract number protocol (including
PyNumber_And()
, PyNumber_Subtract()
, PyNumber_Or()
,
PyNumber_Xor()
, PyNumber_InPlaceAnd()
,
PyNumber_InPlaceSubtract()
, PyNumber_InPlaceOr()
, and
PyNumber_InPlaceXor()
).
PySetObject
PyObject
is used to hold the internal data for both set
and frozenset
objects. It is like a PyDictObject
in that it is a fixed size for small sets (much like tuple storage) and will point to a separate, variable sized block of memory for medium and large sized sets (much like list storage). None of the fields of this structure should be considered public and are subject to change. All access should be done through the documented API rather than by manipulating the values in the structure.PySet_Type
PyTypeObject
representing the Python set
type.PyFrozenSet_Type
PyTypeObject
representing the Python frozenset
type.The following type check macros work on pointers to any Python object. Likewise, the constructor functions work with any iterable Python object.
PySet_Check
(PyObject *p)Return true if p is a set
object or an instance of a subtype.
New in version 2.6.
PyFrozenSet_Check
(PyObject *p)Return true if p is a frozenset
object or an instance of a
subtype.
New in version 2.6.
PyAnySet_Check
(PyObject *p)set
object, a frozenset
object, or an instance of a subtype.PyAnySet_CheckExact
(PyObject *p)set
object or a frozenset
object but not an instance of a subtype.PyFrozenSet_CheckExact
(PyObject *p)frozenset
object but not an instance of a subtype.PySet_New
(PyObject *iterable)Return value: New reference.
Return a new set
containing objects returned by the iterable. The
iterable may be NULL to create a new empty set. Return the new set on
success or NULL on failure. Raise TypeError
if iterable is not
actually iterable. The constructor is also useful for copying a set
(c=set(s)
).
PyFrozenSet_New
(PyObject *iterable)Return value: New reference.
Return a new frozenset
containing objects returned by the iterable.
The iterable may be NULL to create a new empty frozenset. Return the new
set on success or NULL on failure. Raise TypeError
if iterable is
not actually iterable.
Changed in version 2.6: Now guaranteed to return a brand-new frozenset
. Formerly,
frozensets of zero-length were a singleton. This got in the way of
building-up new frozensets with PySet_Add()
.
The following functions and macros are available for instances of set
or frozenset
or instances of their subtypes.
PySet_Size
(PyObject *anyset)Return the length of a set
or frozenset
object. Equivalent to
len(anyset)
. Raises a PyExc_SystemError
if anyset is not a
set
, frozenset
, or an instance of a subtype.
Changed in version 2.5: This function returned an int
. This might require changes in
your code for properly supporting 64-bit systems.
PySet_GET_SIZE
(PyObject *anyset)PySet_Size()
without error checking.PySet_Contains
(PyObject *anyset, PyObject *key)1
if found, 0
if not found, and -1
if an error is encountered. Unlike the Python __contains__()
method, this function does not automatically convert unhashable sets into temporary frozensets. Raise a TypeError
if the key is unhashable. Raise PyExc_SystemError
if anyset is not a set
, frozenset
, or an instance of a subtype.PySet_Add
(PyObject *set, PyObject *key)Add key to a set
instance. Does not apply to frozenset
instances. Return 0
on success or -1
on failure. Raise a TypeError
if
the key is unhashable. Raise a MemoryError
if there is no room to grow.
Raise a SystemError
if set is not an instance of set
or its
subtype.
Changed in version 2.6: Now works with instances of frozenset
or its subtypes.
Like PyTuple_SetItem()
in that it can be used to fill-in the
values of brand new frozensets before they are exposed to other code.
The following functions are available for instances of set
or its
subtypes but not for instances of frozenset
or its subtypes.
PySet_Discard
(PyObject *set, PyObject *key)1
if found and removed, 0
if not found (no action taken), and -1
if an error is encountered. Does not raise KeyError
for missing keys. Raise a TypeError
if the key is unhashable. Unlike the Python discard()
method, this function does not automatically convert unhashable sets into temporary frozensets. Raise PyExc_SystemError
if set is not an instance of set
or its subtype.PySet_Pop
(PyObject *set)Return value: New reference.
Return a new reference to an arbitrary object in the set, and removes the
object from the set. Return NULL on failure. Raise KeyError
if the
set is empty. Raise a SystemError
if set is not an instance of
set
or its subtype.
PySet_Clear
(PyObject *set)