Object Protocol¶
- PyObject*Py_GetConstant(unsignedintconstant_id)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
Get astrong reference to a constant.
Set an exception and return
NULL
ifconstant_id is invalid.constant_id must be one of these constant identifiers:
Constant Identifier
Value
Returned object
- Py_CONSTANT_NONE¶
0
- Py_CONSTANT_FALSE¶
1
- Py_CONSTANT_TRUE¶
2
- Py_CONSTANT_ELLIPSIS¶
3
- Py_CONSTANT_NOT_IMPLEMENTED¶
4
- Py_CONSTANT_ZERO¶
5
0
- Py_CONSTANT_ONE¶
6
1
- Py_CONSTANT_EMPTY_STR¶
7
''
- Py_CONSTANT_EMPTY_BYTES¶
8
b''
- Py_CONSTANT_EMPTY_TUPLE¶
9
()
Numeric values are only given for projects which cannot use the constantidentifiers.
Added in version 3.13.
Λεπτομέρεια υλοποίησης CPython: In CPython, all of these constants areimmortal.
- Py_CONSTANT_NONE¶
- PyObject*Py_GetConstantBorrowed(unsignedintconstant_id)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
Similar to
Py_GetConstant()
, but return aborrowedreference.This function is primarily intended for backwards compatibility:using
Py_GetConstant()
is recommended for new code.The reference is borrowed from the interpreter, and is valid until theinterpreter finalization.
Added in version 3.13.
- PyObject*Py_NotImplemented¶
The
NotImplemented
singleton, used to signal that an operation isnot implemented for the given type combination.
- Py_RETURN_NOTIMPLEMENTED¶
Properly handle returning
Py_NotImplemented
from within a Cfunction (that is, create a newstrong referencetoNotImplemented
and return it).
- Py_PRINT_RAW¶
Flag to be used with multiple functions that print the object (like
PyObject_Print()
andPyFile_WriteObject()
).If passed, these function would use thestr()
of the objectinstead of therepr()
.
- intPyObject_Print(PyObject*o,FILE*fp,intflags)¶
Print an objecto, on filefp. Returns
-1
on error. The flags argumentis used to enable certain printing options. The only option currently supportedisPy_PRINT_RAW
; if given, thestr()
of the object is writteninstead of therepr()
.
- intPyObject_HasAttrWithError(PyObject*o,PyObject*attr_name)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
Returns
1
ifo has the attributeattr_name, and0
otherwise.This is equivalent to the Python expressionhasattr(o,attr_name)
.On failure, return-1
.Added in version 3.13.
- intPyObject_HasAttrStringWithError(PyObject*o,constchar*attr_name)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
This is the same as
PyObject_HasAttrWithError()
, butattr_name isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.Added in version 3.13.
- intPyObject_HasAttr(PyObject*o,PyObject*attr_name)¶
- Μέρος τουΣταθερό ABI.
Returns
1
ifo has the attributeattr_name, and0
otherwise.This function always succeeds.Σημείωση
Exceptions that occur when this calls
__getattr__()
and__getattribute__()
methods aren’t propagated,but instead given tosys.unraisablehook()
.For proper error handling, usePyObject_HasAttrWithError()
,PyObject_GetOptionalAttr()
orPyObject_GetAttr()
instead.
- intPyObject_HasAttrString(PyObject*o,constchar*attr_name)¶
- Μέρος τουΣταθερό ABI.
This is the same as
PyObject_HasAttr()
, butattr_name isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.Σημείωση
Exceptions that occur when this calls
__getattr__()
and__getattribute__()
methods or while creating the temporarystr
object are silently ignored.For proper error handling, usePyObject_HasAttrStringWithError()
,PyObject_GetOptionalAttrString()
orPyObject_GetAttrString()
instead.
- PyObject*PyObject_GetAttr(PyObject*o,PyObject*attr_name)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Retrieve an attribute namedattr_name from objecto. Returns the attributevalue on success, or
NULL
on failure. This is the equivalent of the Pythonexpressiono.attr_name
.If the missing attribute should not be treated as a failure, you can use
PyObject_GetOptionalAttr()
instead.
- PyObject*PyObject_GetAttrString(PyObject*o,constchar*attr_name)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
This is the same as
PyObject_GetAttr()
, butattr_name isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.If the missing attribute should not be treated as a failure, you can use
PyObject_GetOptionalAttrString()
instead.
- intPyObject_GetOptionalAttr(PyObject*obj,PyObject*attr_name,PyObject**result);¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
Variant of
PyObject_GetAttr()
which doesn’t raiseAttributeError
if the attribute is not found.If the attribute is found, return
1
and set*result to a newstrong reference to the attribute.If the attribute is not found, return0
and set*result toNULL
;theAttributeError
is silenced.If an error other thanAttributeError
is raised, return-1
andset*result toNULL
.Added in version 3.13.
- intPyObject_GetOptionalAttrString(PyObject*obj,constchar*attr_name,PyObject**result);¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
This is the same as
PyObject_GetOptionalAttr()
, butattr_name isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.Added in version 3.13.
- PyObject*PyObject_GenericGetAttr(PyObject*o,PyObject*name)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Generic attribute getter function that is meant to be put into a typeobject’s
tp_getattro
slot. It looks for a descriptor in the dictionaryof classes in the object’s MRO as well as an attribute in the object’s__dict__
(if present). As outlined inImplementing Descriptors,data descriptors take preference over instance attributes, while non-datadescriptors don’t. Otherwise, anAttributeError
is raised.
- intPyObject_SetAttr(PyObject*o,PyObject*attr_name,PyObject*v)¶
- Μέρος τουΣταθερό ABI.
Set the value of the attribute namedattr_name, for objecto, to the valuev. Raise an exception and return
-1
on failure;return0
on success. This is the equivalent of the Python statemento.attr_name=v
.Ifv is
NULL
, the attribute is deleted. This behaviour is deprecatedin favour of usingPyObject_DelAttr()
, but there are currently noplans to remove it.
- intPyObject_SetAttrString(PyObject*o,constchar*attr_name,PyObject*v)¶
- Μέρος τουΣταθερό ABI.
This is the same as
PyObject_SetAttr()
, butattr_name isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.Ifv is
NULL
, the attribute is deleted, but this feature isdeprecated in favour of usingPyObject_DelAttrString()
.The number of different attribute names passed to this functionshould be kept small, usually by using a statically allocated stringasattr_name.For attribute names that aren’t known at compile time, prefer calling
PyUnicode_FromString()
andPyObject_SetAttr()
directly.For more details, seePyUnicode_InternFromString()
, which may beused internally to create a key object.
- intPyObject_GenericSetAttr(PyObject*o,PyObject*name,PyObject*value)¶
- Μέρος τουΣταθερό ABI.
Generic attribute setter and deleter function that is meantto be put into a type object’s
tp_setattro
slot. It looks for a data descriptor in thedictionary of classes in the object’s MRO, and if found it takes preferenceover setting or deleting the attribute in the instance dictionary. Otherwise, theattribute is set or deleted in the object’s__dict__
(if present).On success,0
is returned, otherwise anAttributeError
is raised and-1
is returned.
- intPyObject_DelAttr(PyObject*o,PyObject*attr_name)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
Delete attribute namedattr_name, for objecto. Returns
-1
on failure.This is the equivalent of the Python statementdelo.attr_name
.
- intPyObject_DelAttrString(PyObject*o,constchar*attr_name)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.13.
This is the same as
PyObject_DelAttr()
, butattr_name isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.The number of different attribute names passed to this functionshould be kept small, usually by using a statically allocated stringasattr_name.For attribute names that aren’t known at compile time, prefer calling
PyUnicode_FromString()
andPyObject_DelAttr()
directly.For more details, seePyUnicode_InternFromString()
, which may beused internally to create a key object for lookup.
- PyObject*PyObject_GenericGetDict(PyObject*o,void*context)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI από την έκδοση 3.10.
A generic implementation for the getter of a
__dict__
descriptor. Itcreates the dictionary if necessary.This function may also be called to get the
__dict__
of the objecto. PassNULL
forcontext when calling it.Since this function may need to allocate memory for thedictionary, it may be more efficient to callPyObject_GetAttr()
when accessing an attribute on the object.On failure, returns
NULL
with an exception set.Added in version 3.3.
- intPyObject_GenericSetDict(PyObject*o,PyObject*value,void*context)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.7.
A generic implementation for the setter of a
__dict__
descriptor. Thisimplementation does not allow the dictionary to be deleted.Added in version 3.3.
- PyObject**_PyObject_GetDictPtr(PyObject*obj)¶
Return a pointer to
__dict__
of the objectobj.If there is no__dict__
, returnNULL
without setting an exception.This function may need to allocate memory for thedictionary, so it may be more efficient to call
PyObject_GetAttr()
when accessing an attribute on the object.
- PyObject*PyObject_RichCompare(PyObject*o1,PyObject*o2,intopid)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Compare the values ofo1 ando2 using the operation specified byopid,which must be one of
Py_LT
,Py_LE
,Py_EQ
,Py_NE
,Py_GT
, orPy_GE
, corresponding to<
,<=
,==
,!=
,>
, or>=
respectively. This is the equivalent ofthe Python expressiono1opo2
, whereop
is the operator correspondingtoopid. Returns the value of the comparison on success, orNULL
on failure.
- intPyObject_RichCompareBool(PyObject*o1,PyObject*o2,intopid)¶
- Μέρος τουΣταθερό ABI.
Compare the values ofo1 ando2 using the operation specified byopid,like
PyObject_RichCompare()
, but returns-1
on error,0
ifthe result is false,1
otherwise.
Σημείωση
Ifo1 ando2 are the same object,PyObject_RichCompareBool()
will always return1
forPy_EQ
and0
forPy_NE
.
- PyObject*PyObject_Format(PyObject*obj,PyObject*format_spec)¶
- Μέρος τουΣταθερό ABI.
Formatobj usingformat_spec. This is equivalent to the Pythonexpression
format(obj,format_spec)
.format_spec may be
NULL
. In this case the call is equivalenttoformat(obj)
.Returns the formatted string on success,NULL
on failure.
- PyObject*PyObject_Repr(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Compute a string representation of objecto. Returns the stringrepresentation on success,
NULL
on failure. This is the equivalent of thePython expressionrepr(o)
. Called by therepr()
built-in function.Άλλαξε στην έκδοση 3.4:This function now includes a debug assertion to help ensure that itdoes not silently discard an active exception.
- PyObject*PyObject_ASCII(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
As
PyObject_Repr()
, compute a string representation of objecto, butescape the non-ASCII characters in the string returned byPyObject_Repr()
with\x
,\u
or\U
escapes. This generatesa string similar to that returned byPyObject_Repr()
in Python 2.Called by theascii()
built-in function.
- PyObject*PyObject_Str(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Compute a string representation of objecto. Returns the stringrepresentation on success,
NULL
on failure. This is the equivalent of thePython expressionstr(o)
. Called by thestr()
built-in functionand, therefore, by theprint()
function.Άλλαξε στην έκδοση 3.4:This function now includes a debug assertion to help ensure that itdoes not silently discard an active exception.
- PyObject*PyObject_Bytes(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Compute a bytes representation of objecto.
NULL
is returned onfailure and a bytes object on success. This is equivalent to the Pythonexpressionbytes(o)
, wheno is not an integer. Unlikebytes(o)
,a TypeError is raised wheno is an integer instead of a zero-initializedbytes object.
- intPyObject_IsSubclass(PyObject*derived,PyObject*cls)¶
- Μέρος τουΣταθερό ABI.
Return
1
if the classderived is identical to or derived from the classcls, otherwise return0
. In case of an error, return-1
.Ifcls is a tuple, the check will be done against every entry incls.The result will be
1
when at least one of the checks returns1
,otherwise it will be0
.Ifcls has a
__subclasscheck__()
method, it will be called todetermine the subclass status as described inPEP 3119. Otherwise,derived is a subclass ofcls if it is a direct or indirect subclass,i.e. contained incls.__mro__
.Normally only class objects, i.e. instances of
type
or a derivedclass, are considered classes. However, objects can override this by havinga__bases__
attribute (which must be a tuple of base classes).
- intPyObject_IsInstance(PyObject*inst,PyObject*cls)¶
- Μέρος τουΣταθερό ABI.
Return
1
ifinst is an instance of the classcls or a subclass ofcls, or0
if not. On error, returns-1
and sets an exception.Ifcls is a tuple, the check will be done against every entry incls.The result will be
1
when at least one of the checks returns1
,otherwise it will be0
.Ifcls has a
__instancecheck__()
method, it will be called todetermine the subclass status as described inPEP 3119. Otherwise,instis an instance ofcls if its class is a subclass ofcls.An instanceinst can override what is considered its class by having a
__class__
attribute.An objectcls can override if it is considered a class, and what its baseclasses are, by having a
__bases__
attribute (which must be a tupleof base classes).
- Py_hash_tPyObject_Hash(PyObject*o)¶
- Μέρος τουΣταθερό ABI.
Compute and return the hash value of an objecto. On failure, return
-1
.This is the equivalent of the Python expressionhash(o)
.Άλλαξε στην έκδοση 3.2:The return type is now Py_hash_t. This is a signed integer the same sizeas
Py_ssize_t
.
- Py_hash_tPyObject_HashNotImplemented(PyObject*o)¶
- Μέρος τουΣταθερό ABI.
Set a
TypeError
indicating thattype(o)
is nothashable and return-1
.This function receives special treatment when stored in atp_hash
slot,allowing a type to explicitly indicate to the interpreter that it is nothashable.
- intPyObject_IsTrue(PyObject*o)¶
- Μέρος τουΣταθερό ABI.
Returns
1
if the objecto is considered to be true, and0
otherwise.This is equivalent to the Python expressionnotnoto
. On failure, return-1
.
- intPyObject_Not(PyObject*o)¶
- Μέρος τουΣταθερό ABI.
Returns
0
if the objecto is considered to be true, and1
otherwise.This is equivalent to the Python expressionnoto
. On failure, return-1
.
- PyObject*PyObject_Type(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Wheno is non-
NULL
, returns a type object corresponding to the object typeof objecto. On failure, raisesSystemError
and returnsNULL
. Thisis equivalent to the Python expressiontype(o)
.This function creates a newstrong reference to the return value.There’s really no reason to use thisfunction instead of thePy_TYPE()
function, which returns apointer of typePyTypeObject*, except when a newstrong reference is needed.
- intPyObject_TypeCheck(PyObject*o,PyTypeObject*type)¶
Return non-zero if the objecto is of typetype or a subtype oftype, and
0
otherwise. Both parameters must be non-NULL
.
- Py_ssize_tPyObject_Size(PyObject*o)¶
- Py_ssize_tPyObject_Length(PyObject*o)¶
- Μέρος τουΣταθερό ABI.
Return the length of objecto. If the objecto provides either the sequenceand mapping protocols, the sequence length is returned. On error,
-1
isreturned. This is the equivalent to the Python expressionlen(o)
.
- Py_ssize_tPyObject_LengthHint(PyObject*o,Py_ssize_tdefaultvalue)¶
Return an estimated length for the objecto. First try to return itsactual length, then an estimate using
__length_hint__()
, andfinally return the default value. On error return-1
. This is theequivalent to the Python expressionoperator.length_hint(o,defaultvalue)
.Added in version 3.4.
- PyObject*PyObject_GetItem(PyObject*o,PyObject*key)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
Return element ofo corresponding to the objectkey or
NULL
on failure.This is the equivalent of the Python expressiono[key]
.
- intPyObject_SetItem(PyObject*o,PyObject*key,PyObject*v)¶
- Μέρος τουΣταθερό ABI.
Map the objectkey to the valuev. Raise an exception andreturn
-1
on failure; return0
on success. This is theequivalent of the Python statemento[key]=v
. This functiondoesnot steal a reference tov.
- intPyObject_DelItem(PyObject*o,PyObject*key)¶
- Μέρος τουΣταθερό ABI.
Remove the mapping for the objectkey from the objecto. Return
-1
on failure. This is equivalent to the Python statementdelo[key]
.
- intPyObject_DelItemString(PyObject*o,constchar*key)¶
- Μέρος τουΣταθερό ABI.
This is the same as
PyObject_DelItem()
, butkey isspecified as aconstchar* UTF-8 encoded bytes string,rather than aPyObject*.
- PyObject*PyObject_Dir(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
This is equivalent to the Python expression
dir(o)
, returning a (possiblyempty) list of strings appropriate for the object argument, orNULL
if therewas an error. If the argument isNULL
, this is like the Pythondir()
,returning the names of the current locals; in this case, if no execution frameis active thenNULL
is returned butPyErr_Occurred()
will return false.
- PyObject*PyObject_GetIter(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
This is equivalent to the Python expression
iter(o)
. It returns a newiterator for the object argument, or the object itself if the object is alreadyan iterator. RaisesTypeError
and returnsNULL
if the object cannot beiterated.
- PyObject*PyObject_SelfIter(PyObject*obj)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI.
This is equivalent to the Python
__iter__(self):returnself
method.It is intended foriterator types, to be used in thePyTypeObject.tp_iter
slot.
- PyObject*PyObject_GetAIter(PyObject*o)¶
- Επιστρεφόμενη τιμή: New reference. Μέρος τουΣταθερό ABI από την έκδοση 3.10.
This is the equivalent to the Python expression
aiter(o)
. Takes anAsyncIterable
object and returns anAsyncIterator
for it.This is typically a new iterator but if the argument is anAsyncIterator
, this returns itself. RaisesTypeError
andreturnsNULL
if the object cannot be iterated.Added in version 3.10.
- void*PyObject_GetTypeData(PyObject*o,PyTypeObject*cls)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.12.
Get a pointer to subclass-specific data reserved forcls.
The objecto must be an instance ofcls, andcls must have beencreated using negative
PyType_Spec.basicsize
.Python does not check this.On error, set an exception and return
NULL
.Added in version 3.12.
- Py_ssize_tPyType_GetTypeDataSize(PyTypeObject*cls)¶
- Μέρος τουΣταθερό ABI από την έκδοση 3.12.
Return the size of the instance memory space reserved forcls, i.e. the size of thememory
PyObject_GetTypeData()
returns.This may be larger than requested using
-PyType_Spec.basicsize
;it is safe to use this larger size (e.g. withmemset()
).The typeclsmust have been created usingnegative
PyType_Spec.basicsize
.Python does not check this.On error, set an exception and return a negative value.
Added in version 3.12.
- void*PyObject_GetItemData(PyObject*o)¶
Get a pointer to per-item data for a class with
Py_TPFLAGS_ITEMS_AT_END
.On error, set an exception and return
NULL
.TypeError
is raised ifo does not havePy_TPFLAGS_ITEMS_AT_END
set.Added in version 3.12.
- intPyObject_VisitManagedDict(PyObject*obj,visitprocvisit,void*arg)¶
Visit the managed dictionary ofobj.
This function must only be called in a traverse function of the type whichhas the
Py_TPFLAGS_MANAGED_DICT
flag set.Added in version 3.13.
- voidPyObject_ClearManagedDict(PyObject*obj)¶
Clear the managed dictionary ofobj.
This function must only be called in a traverse function of the type whichhas the
Py_TPFLAGS_MANAGED_DICT
flag set.Added in version 3.13.
- intPyUnstable_Object_EnableDeferredRefcount(PyObject*obj)¶
- Αυτό είναιΑσταθές API. Μπορεί να αλλάξει χωρίς προειδοποίηση σε μικρές εκδόσεις.
Enabledeferred reference counting onobj,if supported by the runtime. In thefree-threaded build,this allows the interpreter to avoid reference count adjustments toobj,which may improve multi-threaded performance. The tradeoff isthatobj will only be deallocated by the tracing garbage collector.
This function returns
1
if deferred reference counting is enabled onobj(including when it was enabled before the call),and0
if deferred reference counting is not supported or if the hint wasignored by the runtime. This function is thread-safe, and cannot fail.This function does nothing on builds with theGIL enabled, which donot support deferred reference counting. This also does nothing ifobj is notan object tracked by the garbage collector (see
gc.is_tracked()
andPyObject_GC_IsTracked()
).This function is intended to be used soon afterobj is created,by the code that creates it.
Added in version 3.14.
- intPyUnstable_Object_IsUniqueReferencedTemporary(PyObject*obj)¶
- Αυτό είναιΑσταθές API. Μπορεί να αλλάξει χωρίς προειδοποίηση σε μικρές εκδόσεις.
Check ifobj is a unique temporary object.Returns
1
ifobj is known to be a unique temporary object,and0
otherwise. This function cannot fail, but the check isconservative, and may return0
in some cases even ifobj is a uniquetemporary object.If an object is a unique temporary, it is guaranteed that the current codehas the only reference to the object. For arguments to C functions, thisshould be used instead of checking if the reference count is
1
. Startingwith Python 3.14, the interpreter internally avoids some reference countmodifications when loading objects onto the operands stack byborrowing references when possible, which meansthat a reference count of1
by itself does not guarantee that a functionargument uniquely referenced.In the example below,
my_func
is called with a unique temporary objectas its argument:my_func([1,2,3])
In the example below,
my_func
isnot called with a unique temporaryobject as its argument, even if its refcount is1
:my_list=[1,2,3]my_func(my_list)
See also the function
Py_REFCNT()
.Added in version 3.14.
- intPyUnstable_IsImmortal(PyObject*obj)¶
- Αυτό είναιΑσταθές API. Μπορεί να αλλάξει χωρίς προειδοποίηση σε μικρές εκδόσεις.
This function returns non-zero ifobj isimmortal, and zerootherwise. This function cannot fail.
Σημείωση
Objects that are immortal in one CPython version are not guaranteed tobe immortal in another.
Added in version 3.14.
- intPyUnstable_TryIncRef(PyObject*obj)¶
- Αυτό είναιΑσταθές API. Μπορεί να αλλάξει χωρίς προειδοποίηση σε μικρές εκδόσεις.
Increments the reference count ofobj if it is not zero. Returns
1
if the object’s reference count was successfully incremented. Otherwise,this function returns0
.PyUnstable_EnableTryIncRef()
must have been calledearlier onobj or this function may spuriously return0
in thefree threading build.This function is logically equivalent to the following C code, except thatit behaves atomically in thefree threading build:
if(Py_REFCNT(op)>0){Py_INCREF(op);return1;}return0;
This is intended as a building block for managing weak referenceswithout the overhead of a Pythonweak reference object.
Typically, correct use of this function requires support fromobj’sdeallocator (
tp_dealloc
).For example, the following sketch could be adapted to implement a«weakmap» that works like aWeakValueDictionary
for a specific type:PyMutexmutex;PyObject*add_entry(weakmap_key_type*key,PyObject*value){PyUnstable_EnableTryIncRef(value);weakmap_typeweakmap=...;PyMutex_Lock(&mutex);weakmap_add_entry(weakmap,key,value);PyMutex_Unlock(&mutex);Py_RETURN_NONE;}PyObject*get_value(weakmap_key_type*key){weakmap_typeweakmap=...;PyMutex_Lock(&mutex);PyObject*result=weakmap_find(weakmap,key);if(PyUnstable_TryIncRef(result)){// `result` is safe to usePyMutex_Unlock(&mutex);returnresult;}// if we get here, `result` is starting to be garbage-collected,// but has not been removed from the weakmap yetPyMutex_Unlock(&mutex);returnNULL;}// tp_dealloc function for weakmap valuesvoidvalue_dealloc(PyObject*value){weakmap_typeweakmap=...;PyMutex_Lock(&mutex);weakmap_remove_value(weakmap,value);...PyMutex_Unlock(&mutex);}
Added in version 3.14.
- voidPyUnstable_EnableTryIncRef(PyObject*obj)¶
- Αυτό είναιΑσταθές API. Μπορεί να αλλάξει χωρίς προειδοποίηση σε μικρές εκδόσεις.
Enables subsequent uses of
PyUnstable_TryIncRef()
onobj. Thecaller must hold astrong reference toobj when calling this.Added in version 3.14.
- intPyUnstable_Object_IsUniquelyReferenced(PyObject*op)¶
- Αυτό είναιΑσταθές API. Μπορεί να αλλάξει χωρίς προειδοποίηση σε μικρές εκδόσεις.
Determine ifop only has one reference.
On GIL-enabled builds, this function is equivalent toPy_REFCNT(op)==1.
On afree threaded build, this checks ifop’sreference count is equal to one and additionally checks ifopis only used by this thread.Py_REFCNT(op)==1 isnotthread-safe on free threaded builds; prefer this function.
The caller must hold anattached thread state, despite the factthat this function doesn’t call into the Python interpreter. This functioncannot fail.
Added in version 3.14.