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
This subtype of 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.
PyTypeObject PySet_Type
This is an instance of PyTypeObject representing the Python
set type.
PyTypeObject PyFrozenSet_Type
This is an instance of 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.
int PySet_Check(PyObject *p)
Return true if p is a set object or an instance of a subtype.
int PyFrozenSet_Check(PyObject *p)
Return true if p is a frozenset object or an instance of a
subtype.
int PyAnySet_Check(PyObject *p)
Return true if p is a set object, a frozenset object, or an
instance of a subtype.
int PyAnySet_CheckExact(PyObject *p)
Return true if p is a set object or a frozenset object but
not an instance of a subtype.
int PyFrozenSet_CheckExact(PyObject *p)
Return true if p is a frozenset object but not an instance of a
subtype.
PyObject* 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)).
PyObject* 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.
The following functions and macros are available for instances of set
or frozenset or instances of their subtypes.
Py_ssize_t 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.
Py_ssize_t PySet_GET_SIZE(PyObject *anyset)
Macro form of PySet_Size() without error checking.
int PySet_Contains(PyObject *anyset, PyObject *key)
Return 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.
int PySet_Add(PyObject *set, PyObject *key)
Add key to a set instance. Also works with frozenset
instances (like PyTuple_SetItem() it can be used to fill-in the values
of brand new frozensets before they are exposed to other code). 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.
The following functions are available for instances of set or its
subtypes but not for instances of frozenset or its subtypes.
int PySet_Discard(PyObject *set, PyObject *key)
Return 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.
PyObject* 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.
int PySet_Clear(PyObject *set)
Empty an existing set of all elements.
int PySet_ClearFreeList()
Clear the free list. Return the total number of freed items.
New in version 3.3.