PyTypeObject
¶
The C structure of the objects used to describe built-in types.
PyType_Type
¶
This is the type object for type objects; it is the same object as
type
在 Python 层。
PyType_Check
(
PyObject
*o
)
¶
Return true if the object o is a type object, including instances of types derived from the standard type object. Return false in all other cases.
PyType_CheckExact
(
PyObject
*o
)
¶
Return true if the object o is a type object, but not a subtype of the standard type object. Return false in all other cases.
PyType_ClearCache
(
)
¶
Clear the internal lookup cache. Return the current version tag.
PyType_GetFlags
(
PyTypeObject
*
type
)
¶
返回
tp_flags
member of
type
. This function is primarily meant for use with
Py_LIMITED_API
; the individual flag bits are guaranteed to be stable across Python releases, but access to
tp_flags
itself is not part of the limited API.
3.2 版新增。
3.4 版改变:
The return type is now
unsigned long
而不是
long
.
PyType_Modified
(
PyTypeObject
*type
)
¶
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.
PyType_HasFeature
(
PyTypeObject
*o
, int
feature
)
¶
Return true if the type object o sets the feature feature . Type features are denoted by single bit flags.
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
.
PyType_IsSubtype
(
PyTypeObject
*a
,
PyTypeObject
*b
)
¶
返回 True 若 a is a subtype of b .
This function only checks for actual subtypes, which means that
__subclasscheck__()
is not called on
b
。调用
PyObject_IsSubclass()
to do the same check that
issubclass()
would do.
PyType_GenericAlloc
(
PyTypeObject
*type
, Py_ssize_t
nitems
)
¶
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 to
NULL
.
PyType_GenericNew
(
PyTypeObject
*type
,
PyObject
*args
,
PyObject
*kwds
)
¶
Generic handler for the
tp_new
slot of a type object. Create a new instance using the type’s
tp_alloc
槽。
PyType_Ready
(
PyTypeObject
*type
)
¶
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.
PyType_GetSlot
(
PyTypeObject
*type
, int
slot
)
¶
Return the function pointer stored in the given slot. If the result is
NULL
, this indicates that either the slot is
NULL
, or that the function was called with invalid parameters. Callers will typically cast the result pointer into the appropriate function type.
见
PyType_Slot.slot
for possible values of the
slot
自变量。
An exception is raised if type is not a heap type.
3.4 版新增。
The following functions and structs are used to create heap types .
PyType_FromSpecWithBases
(
PyType_Spec
*spec
,
PyObject
*bases
)
¶
Creates and returns a heap type object from the
spec
(
Py_TPFLAGS_HEAPTYPE
).
若 bases is a tuple, the created heap type contains all types contained in it as base types.
若
bases
is
NULL
,
Py_tp_bases
slot is used instead. If that also is
NULL
,
Py_tp_base
slot is used instead. If that also is
NULL
, the new type derives from
object
.
此函数调用
PyType_Ready()
on the new type.
3.3 版新增。
PyType_FromSpec
(
PyType_Spec
*spec
)
¶
相当于
PyType_FromSpecWithBases(spec, NULL)
.
PyType_Spec
¶
Structure defining a type’s behavior.
PyType_Spec.name
¶
Name of the type, used to set
PyTypeObject.tp_name
.
PyType_Spec.basicsize
¶
PyType_Spec.itemsize
¶
Size of the instance in bytes, used to set
PyTypeObject.tp_basicsize
and
PyTypeObject.tp_itemsize
.
PyType_Spec.flags
¶
Type flags, used to set
PyTypeObject.tp_flags
.
若
Py_TPFLAGS_HEAPTYPE
flag is not set,
PyType_FromSpecWithBases()
sets it automatically.
PyType_Spec.slots
¶
Array of
PyType_Slot
structures. Terminated by the special slot value
{0, NULL}
.
PyType_Slot
¶
Structure defining optional functionality of a type, containing a slot ID and a value pointer.
PyType_Slot.slot
¶
A slot ID.
Slot IDs are named like the field names of the structures
PyTypeObject
,
PyNumberMethods
,
PySequenceMethods
,
PyMappingMethods
and
PyAsyncMethods
with an added
Py_
prefix. For example, use:
Py_tp_dealloc
to set
PyTypeObject.tp_dealloc
Py_nb_add
to set
PyNumberMethods.nb_add
Py_sq_length
to set
PySequenceMethods.sq_length
The following fields cannot be set using
PyType_Spec
and
PyType_Slot
:
tp_print
设置
Py_tp_bases
or
Py_tp_base
may be problematic on some platforms. To avoid issues, use the
bases
自变量
PyType_FromSpecWithBases()
代替。
PyType_Slot.pfunc
¶
The desired value of the slot. In most cases, this is a pointer to a function.
May not be
NULL
.