Object Protocol¶
-
PyObject*Py_NotImplemented¶
The
NotImplemented
singleton, used to signal that an operation is not implemented for the given type combination.
-
Py_RETURN_NOTIMPLEMENTED¶
Properly handle returning
Py_NotImplemented
from within a C function (that is, create a newstrong reference toNotImplemented
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 object instead of therepr()
.
-
intPyObject_Print(PyObject*o,FILE*fp,intflags)¶
Print an objecto,on filefp.Returns
-1
on error. The flags argument is used to enable certain printing options. The only option currently supported isPy_PRINT_RAW
;if given, thestr()
of the object is written instead of therepr()
.
-
intPyObject_HasAttr(PyObject*o,PyObject*attr_name)¶
- Part of theStable ABI.
Returns
1
ifohas the attributeattr_name,and0
otherwise. This is equivalent to the Python expressionhasattr(o,attr_name)
.This function always succeeds.Note
Exceptions that occur when this calls
__getattr__()
and__getattribute__()
methods are silently ignored. For proper error handling, usePyObject_GetAttr()
instead.
-
intPyObject_HasAttrString(PyObject*o,constchar*attr_name)¶
- Part of theStable ABI.
This is the same as
PyObject_HasAttr()
,butattr_nameis specified as aconstchar*UTF-8 encoded bytes string, rather than aPyObject*.Note
Exceptions that occur when this calls
__getattr__()
and__getattribute__()
methods or while creating the temporarystr
object are silently ignored. For proper error handling, usePyObject_GetAttrString()
instead.
-
PyObject*PyObject_GetAttr(PyObject*o,PyObject*attr_name)¶
- Return value: New reference.Part of theStable ABI.
Retrieve an attribute namedattr_namefrom objecto.Returns the attribute value on success, or
NULL
on failure. This is the equivalent of the Python expressiono.attr_name
.
-
PyObject*PyObject_GetAttrString(PyObject*o,constchar*attr_name)¶
- Return value: New reference.Part of theStable ABI.
This is the same as
PyObject_GetAttr()
,butattr_nameis specified as aconstchar*UTF-8 encoded bytes string, rather than aPyObject*.
-
PyObject*PyObject_GenericGetAttr(PyObject*o,PyObject*name)¶
- Return value: New reference.Part of theStable ABI.
Generic attribute getter function that is meant to be put into a type object’s
tp_getattro
slot. It looks for a descriptor in the dictionary of 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-data descriptors don’t. Otherwise, anAttributeError
is raised.
-
intPyObject_SetAttr(PyObject*o,PyObject*attr_name,PyObject*v)¶
- Part of theStable ABI.
Set the value of the attribute namedattr_name,for objecto,to the value v.Raise an exception and return
-1
on failure; return0
on success. This is the equivalent of the Python statemento.attr_name=v
.Ifvis
NULL
,the attribute is deleted. This behaviour is deprecated in favour of usingPyObject_DelAttr()
,but there are currently no plans to remove it.
-
intPyObject_SetAttrString(PyObject*o,constchar*attr_name,PyObject*v)¶
- Part of theStable ABI.
This is the same as
PyObject_SetAttr()
,butattr_nameis specified as aconstchar*UTF-8 encoded bytes string, rather than aPyObject*.Ifvis
NULL
,the attribute is deleted, but this feature is deprecated in favour of usingPyObject_DelAttrString()
.
-
intPyObject_GenericSetAttr(PyObject*o,PyObject*name,PyObject*value)¶
- Part of theStable ABI.
Generic attribute setter and deleter function that is meant to be put into a type object’s
tp_setattro
slot. It looks for a data descriptor in the dictionary of classes in the object’s MRO, and if found it takes preference over setting or deleting the attribute in the instance dictionary. Otherwise, the attribute 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)¶
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)¶
This is the same as
PyObject_DelAttr()
,butattr_nameis specified as aconstchar*UTF-8 encoded bytes string, rather than aPyObject*.
-
PyObject*PyObject_GenericGetDict(PyObject*o,void*context)¶
- Return value: New reference.Part of theStable ABIsince version 3.10.
A generic implementation for the getter of a
__dict__
descriptor. It creates the dictionary if necessary.This function may also be called to get the
__dict__
of the objecto.PassNULL
forcontextwhen calling it. Since this function may need to allocate memory for the dictionary, 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)¶
- Part of theStable ABIsince version 3.7.
A generic implementation for the setter of a
__dict__
descriptor. This implementation 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 the dictionary, 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)¶
- Return value: New reference.Part of theStable ABI.
Compare the values ofo1ando2using 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 of the Python expressiono1opo2
,whereop
is the operator corresponding toopid.Returns the value of the comparison on success, orNULL
on failure.
-
intPyObject_RichCompareBool(PyObject*o1,PyObject*o2,intopid)¶
- Part of theStable ABI.
Compare the values ofo1ando2using the operation specified byopid, like
PyObject_RichCompare()
,but returns-1
on error,0
if the result is false,1
otherwise.
Note
Ifo1ando2are the same object,PyObject_RichCompareBool()
will always return1
forPy_EQ
and0
forPy_NE
.
-
PyObject*PyObject_Format(PyObject*obj,PyObject*format_spec)¶
- Part of theStable ABI.
Formatobjusingformat_spec.This is equivalent to the Python expression
format(obj,format_spec)
.format_specmay be
NULL
.In this case the call is equivalent toformat(obj)
. Returns the formatted string on success,NULL
on failure.
-
PyObject*PyObject_Repr(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
Compute a string representation of objecto.Returns the string representation on success,
NULL
on failure. This is the equivalent of the Python expressionrepr(o)
.Called by therepr()
built-in function.Changed in version 3.4:This function now includes a debug assertion to help ensure that it does not silently discard an active exception.
-
PyObject*PyObject_ASCII(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
As
PyObject_Repr()
,compute a string representation of objecto,but escape the non-ASCII characters in the string returned byPyObject_Repr()
with\x
,\u
or\U
escapes. This generates a string similar to that returned byPyObject_Repr()
in Python 2. Called by theascii()
built-in function.
-
PyObject*PyObject_Str(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
Compute a string representation of objecto.Returns the string representation on success,
NULL
on failure. This is the equivalent of the Python expressionstr(o)
.Called by thestr()
built-in function and, therefore, by theprint()
function.Changed in version 3.4:This function now includes a debug assertion to help ensure that it does not silently discard an active exception.
-
PyObject*PyObject_Bytes(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
Compute a bytes representation of objecto.
NULL
is returned on failure and a bytes object on success. This is equivalent to the Python expressionbytes(o)
,whenois not an integer. Unlikebytes(o)
, a TypeError is raised whenois an integer instead of a zero-initialized bytes object.
-
intPyObject_IsSubclass(PyObject*derived,PyObject*cls)¶
- Part of theStable ABI.
Return
1
if the classderivedis identical to or derived from the class cls,otherwise return0
.In case of an error, return-1
.Ifclsis 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
.Ifclshas a
__subclasscheck__()
method, it will be called to determine the subclass status as described inPEP 3119.Otherwise, derivedis a subclass ofclsif it is a direct or indirect subclass, i.e. contained incls.__mro__
.Normally only class objects, i.e. instances of
type
or a derived class, are considered classes. However, objects can override this by having a__bases__
attribute (which must be a tuple of base classes).
-
intPyObject_IsInstance(PyObject*inst,PyObject*cls)¶
- Part of theStable ABI.
Return
1
ifinstis an instance of the classclsor a subclass of cls,or0
if not. On error, returns-1
and sets an exception.Ifclsis 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
.Ifclshas a
__instancecheck__()
method, it will be called to determine the subclass status as described inPEP 3119.Otherwise,inst is an instance ofclsif its class is a subclass ofcls.An instanceinstcan override what is considered its class by having a
__class__
attribute.An objectclscan override if it is considered a class, and what its base classes are, by having a
__bases__
attribute (which must be a tuple of base classes).
-
Py_hash_tPyObject_Hash(PyObject*o)¶
- Part of theStable ABI.
Compute and return the hash value of an objecto.On failure, return
-1
. This is the equivalent of the Python expressionhash(o)
.Changed in version 3.2:The return type is now Py_hash_t. This is a signed integer the same size as
Py_ssize_t
.
-
Py_hash_tPyObject_HashNotImplemented(PyObject*o)¶
- Part of theStable ABI.
Set a
TypeError
indicating thattype(o)
is nothashableand 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 not hashable.
-
intPyObject_IsTrue(PyObject*o)¶
- Part of theStable ABI.
Returns
1
if the objectois considered to be true, and0
otherwise. This is equivalent to the Python expressionnotnoto
.On failure, return-1
.
-
intPyObject_Not(PyObject*o)¶
- Part of theStable ABI.
Returns
0
if the objectois considered to be true, and1
otherwise. This is equivalent to the Python expressionnoto
.On failure, return-1
.
-
PyObject*PyObject_Type(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
Whenois non-
NULL
,returns a type object corresponding to the object type of objecto.On failure, raisesSystemError
and returnsNULL
.This is equivalent to the Python expressiontype(o)
. This function creates a newstrong referenceto the return value. There’s really no reason to use this function instead of thePy_TYPE()
function, which returns a pointer of typePyTypeObject*,except when a new strong referenceis needed.
-
intPyObject_TypeCheck(PyObject*o,PyTypeObject*type)¶
Return non-zero if the objectois of typetypeor a subtype oftype,and
0
otherwise. Both parameters must be non-NULL
.
-
Py_ssize_tPyObject_Size(PyObject*o)¶
-
Py_ssize_tPyObject_Length(PyObject*o)¶
- Part of theStable ABI.
Return the length of objecto.If the objectoprovides either the sequence and mapping protocols, the sequence length is returned. On error,
-1
is returned. 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 its actual length, then an estimate using
__length_hint__()
,and finally return the default value. On error return-1
.This is the equivalent to the Python expressionoperator.length_hint(o,defaultvalue)
.Added in version 3.4.
-
PyObject*PyObject_GetItem(PyObject*o,PyObject*key)¶
- Return value: New reference.Part of theStable ABI.
Return element ofocorresponding to the objectkeyor
NULL
on failure. This is the equivalent of the Python expressiono[key]
.
-
intPyObject_SetItem(PyObject*o,PyObject*key,PyObject*v)¶
- Part of theStable ABI.
Map the objectkeyto the valuev.Raise an exception and return
-1
on failure; return0
on success. This is the equivalent of the Python statemento[key]=v
.This functiondoes notsteal a reference tov.
-
intPyObject_DelItem(PyObject*o,PyObject*key)¶
- Part of theStable ABI.
Remove the mapping for the objectkeyfrom the objecto.Return
-1
on failure. This is equivalent to the Python statementdelo[key]
.
-
PyObject*PyObject_Dir(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
This is equivalent to the Python expression
dir(o)
,returning a (possibly empty) list of strings appropriate for the object argument, orNULL
if there was an error. If the argument isNULL
,this is like the Pythondir()
, returning the names of the current locals; in this case, if no execution frame is active thenNULL
is returned butPyErr_Occurred()
will return false.
-
PyObject*PyObject_GetIter(PyObject*o)¶
- Return value: New reference.Part of theStable ABI.
This is equivalent to the Python expression
iter(o)
.It returns a new iterator for the object argument, or the object itself if the object is already an iterator. RaisesTypeError
and returnsNULL
if the object cannot be iterated.
-
PyObject*PyObject_GetAIter(PyObject*o)¶
- Return value: New reference.Part of theStable ABIsince version 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
and returnsNULL
if the object cannot be iterated.Added in version 3.10.
-
void*PyObject_GetTypeData(PyObject*o,PyTypeObject*cls)¶
- Part of theStable ABIsince version 3.12.
Get a pointer to subclass-specific data reserved forcls.
The objectomust be an instance ofcls,andclsmust have been created 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)¶
- Part of theStable ABIsince version 3.12.
Return the size of the instance memory space reserved forcls,i.e. the size of the memory
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 typeclsmusthave been created using negative
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 ifodoes not havePy_TPFLAGS_ITEMS_AT_END
set.Added in version 3.12.