Type Objects¶
-
type PyTypeObject¶
- Part of the Limited API (as an opaque struct).
The C structure of the objects used to describe built-in types.
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PyTypeObject PyType_Type¶
- Part of the Stable ABI.
This is the type object for type objects; it is the same object as
type
in the Python layer.
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int PyType_Check(PyObject *o)¶
Return non-zero if the object o is a type object, including instances of types derived from the standard type object. Return 0 in all other cases. This function always succeeds.
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int PyType_CheckExact(PyObject *o)¶
Return non-zero if the object o is a type object, but not a subtype of the standard type object. Return 0 in all other cases. This function always succeeds.
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unsigned int PyType_ClearCache()¶
- Part of the Stable ABI.
Clear the internal lookup cache. Return the current version tag.
-
unsigned long PyType_GetFlags(PyTypeObject *type)¶
- Part of the Stable ABI.
Return the
tp_flags
member of type. This function is primarily meant for use withPy_LIMITED_API
; the individual flag bits are guaranteed to be stable across Python releases, but access totp_flags
itself is not part of the limited API.New in version 3.2.
Changed in version 3.4: The return type is now
unsigned long
rather thanlong
.
-
void PyType_Modified(PyTypeObject *type)¶
- Part of the Stable ABI.
Invalidate the internal lookup cache for the type and all of its subtypes. This function must be called after any manual modification of the attributes or base classes of the type.
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int PyType_HasFeature(PyTypeObject *o, int feature)¶
Return non-zero if the type object o sets the feature feature. Type features are denoted by single bit flags.
-
int PyType_IS_GC(PyTypeObject *o)¶
Return true if the type object includes support for the cycle detector; this tests the type flag
Py_TPFLAGS_HAVE_GC
.
-
int PyType_IsSubtype(PyTypeObject *a, PyTypeObject *b)¶
- Part of the Stable ABI.
Return true if a is a subtype of b.
This function only checks for actual subtypes, which means that
__subclasscheck__()
is not called on b. CallPyObject_IsSubclass()
to do the same check thatissubclass()
would do.
-
PyObject *PyType_GenericAlloc(PyTypeObject *type, Py_ssize_t nitems)¶
- Return value: New reference. Part of the Stable ABI.
Generic handler for the
tp_alloc
slot of a type object. Use Python’s default memory allocation mechanism to allocate a new instance and initialize all its contents toNULL
.
-
PyObject *PyType_GenericNew(PyTypeObject *type, PyObject *args, PyObject *kwds)¶
- Return value: New reference. Part of the Stable ABI.
Generic handler for the
tp_new
slot of a type object. Create a new instance using the type’stp_alloc
slot.
-
int PyType_Ready(PyTypeObject *type)¶
- Part of the Stable ABI.
Finalize a type object. This should be called on all type objects to finish their initialization. This function is responsible for adding inherited slots from a type’s base class. Return
0
on success, or return-1
and sets an exception on error.Note
If some of the base classes implements the GC protocol and the provided type does not include the
Py_TPFLAGS_HAVE_GC
in its flags, then the GC protocol will be automatically implemented from its parents. On the contrary, if the type being created does includePy_TPFLAGS_HAVE_GC
in its flags then it must implement the GC protocol itself by at least implementing thetp_traverse
handle.
-
PyObject *PyType_GetName(PyTypeObject *type)¶
- Return value: New reference. Part of the Stable ABI since version 3.11.
Return the type’s name. Equivalent to getting the type’s
__name__
attribute.New in version 3.11.
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PyObject *PyType_GetQualName(PyTypeObject *type)¶
- Return value: New reference. Part of the Stable ABI since version 3.11.
Return the type’s qualified name. Equivalent to getting the type’s
__qualname__
attribute.New in version 3.11.
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void *PyType_GetSlot(PyTypeObject *type, int slot)¶
- Part of the Stable ABI since version 3.4.
Return the function pointer stored in the given slot. If the result is
NULL
, this indicates that either the slot isNULL
, or that the function was called with invalid parameters. Callers will typically cast the result pointer into the appropriate function type.See
PyType_Slot.slot
for possible values of the slot argument.New in version 3.4.
Changed in version 3.10:
PyType_GetSlot()
can now accept all types. Previously, it was limited to heap types.
-
PyObject *PyType_GetModule(PyTypeObject *type)¶
- Part of the Stable ABI since version 3.10.
Return the module object associated with the given type when the type was created using
PyType_FromModuleAndSpec()
.If no module is associated with the given type, sets
TypeError
and returnsNULL
.This function is usually used to get the module in which a method is defined. Note that in such a method,
PyType_GetModule(Py_TYPE(self))
may not return the intended result.Py_TYPE(self)
may be a subclass of the intended class, and subclasses are not necessarily defined in the same module as their superclass. SeePyCMethod
to get the class that defines the method. SeePyType_GetModuleByDef()
for cases whenPyCMethod
cannot be used.New in version 3.9.
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void *PyType_GetModuleState(PyTypeObject *type)¶
- Part of the Stable ABI since version 3.10.
Return the state of the module object associated with the given type. This is a shortcut for calling
PyModule_GetState()
on the result ofPyType_GetModule()
.If no module is associated with the given type, sets
TypeError
and returnsNULL
.If the type has an associated module but its state is
NULL
, returnsNULL
without setting an exception.New in version 3.9.
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PyObject *PyType_GetModuleByDef(PyTypeObject *type, struct PyModuleDef *def)¶
Find the first superclass whose module was created from the given
PyModuleDef
def, and return that module.If no module is found, raises a
TypeError
and returnsNULL
.This function is intended to be used together with
PyModule_GetState()
to get module state from slot methods (such astp_init
ornb_add
) and other places where a method’s defining class cannot be passed using thePyCMethod
calling convention.New in version 3.11.
Creating Heap-Allocated Types¶
The following functions and structs are used to create heap types.
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PyObject *PyType_FromModuleAndSpec(PyObject *module, PyType_Spec *spec, PyObject *bases)¶
- Return value: New reference. Part of the Stable ABI since version 3.10.
Creates and returns a heap type from the spec (
Py_TPFLAGS_HEAPTYPE
).The bases argument can be used to specify base classes; it can either be only one class or a tuple of classes. If bases is
NULL
, the Py_tp_bases slot is used instead. If that also isNULL
, the Py_tp_base slot is used instead. If that also isNULL
, the new type derives fromobject
.The module argument can be used to record the module in which the new class is defined. It must be a module object or
NULL
. If notNULL
, the module is associated with the new type and can later be retrieved withPyType_GetModule()
. The associated module is not inherited by subclasses; it must be specified for each class individually.This function calls
PyType_Ready()
on the new type.New in version 3.9.
Changed in version 3.10: The function now accepts a single class as the bases argument and
NULL
as thetp_doc
slot.
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PyObject *PyType_FromSpecWithBases(PyType_Spec *spec, PyObject *bases)¶
- Return value: New reference. Part of the Stable ABI since version 3.3.
Equivalent to
PyType_FromModuleAndSpec(NULL, spec, bases)
.New in version 3.3.
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PyObject *PyType_FromSpec(PyType_Spec *spec)¶
- Return value: New reference. Part of the Stable ABI.
Equivalent to
PyType_FromSpecWithBases(spec, NULL)
.
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type PyType_Spec¶
- Part of the Stable ABI (including all members).
Structure defining a type’s behavior.
-
const char *PyType_Spec.name¶
Name of the type, used to set
PyTypeObject.tp_name
.
-
int PyType_Spec.basicsize¶
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int PyType_Spec.itemsize¶
Size of the instance in bytes, used to set
PyTypeObject.tp_basicsize
andPyTypeObject.tp_itemsize
.
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int PyType_Spec.flags¶
Type flags, used to set
PyTypeObject.tp_flags
.If the
Py_TPFLAGS_HEAPTYPE
flag is not set,PyType_FromSpecWithBases()
sets it automatically.
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PyType_Slot *PyType_Spec.slots¶
Array of
PyType_Slot
structures. Terminated by the special slot value{0, NULL}
.
-
const char *PyType_Spec.name¶
-
type PyType_Slot¶
- Part of the Stable ABI (including all members).
Structure defining optional functionality of a type, containing a slot ID and a value pointer.
-
int PyType_Slot.slot¶
A slot ID.
Slot IDs are named like the field names of the structures
PyTypeObject
,PyNumberMethods
,PySequenceMethods
,PyMappingMethods
andPyAsyncMethods
with an addedPy_
prefix. For example, use:Py_tp_dealloc
to setPyTypeObject.tp_dealloc
Py_nb_add
to setPyNumberMethods.nb_add
Py_sq_length
to setPySequenceMethods.sq_length
The following fields cannot be set at all using
PyType_Spec
andPyType_Slot
:tp_weaklistoffset
(see PyMemberDef)tp_dictoffset
(see PyMemberDef)
Setting
Py_tp_bases
orPy_tp_base
may be problematic on some platforms. To avoid issues, use the bases argument ofPyType_FromSpecWithBases()
instead.Changed in version 3.9: Slots in
PyBufferProcs
may be set in the unlimited API.Changed in version 3.11:
bf_getbuffer
andbf_releasebuffer
are now available under the limited API.
-
void *PyType_Slot.pfunc¶
The desired value of the slot. In most cases, this is a pointer to a function.
Slots other than
Py_tp_doc
may not beNULL
.
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int PyType_Slot.slot¶