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, increment the reference count of NotImplemented and return it).
PyObject_Print
Print an object o, on file fp. Returns -1
on error. The flags argument is used to enable certain printing options. The only option currently supported is Py_PRINT_RAW
; if given, the str()
of the object is written instead of the repr()
.
PyObject_HasAttr
Returns 1
if o has the attribute attr_name, and 0
otherwise. This is equivalent to the Python expression hasattr(o, attr_name)
. This function always succeeds.
Note that exceptions which occur while calling __getattr__()
and __getattribute__()
methods will get suppressed. To get error reporting use PyObject_GetAttr()
instead.
PyObject_HasAttrString
Returns 1
if o has the attribute attr_name, and 0
otherwise. This is equivalent to the Python expression hasattr(o, attr_name)
. This function always succeeds.
Note that exceptions which occur while calling __getattr__()
and __getattribute__()
methods and creating a temporary string object will get suppressed. To get error reporting use PyObject_GetAttrString()
instead.
PyObject_GetAttr
Retrieve an attribute named attr_name from object o. Returns the attribute value on success, or NULL
on failure. This is the equivalent of the Python expression o.attr_name
.
PyObject_GetAttrString
Retrieve an attribute named attr_name from object o. Returns the attribute value on success, or NULL
on failure. This is the equivalent of the Python expression o.attr_name
.
PyObject_GenericGetAttr
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 in Implementing Descriptors, data descriptors take preference over instance attributes, while non-data descriptors don?t. Otherwise, an AttributeError
is raised.
PyObject_SetAttr
Set the value of the attribute named attr_name, for object o, to the value v. Raise an exception and return -1
on failure; return 0
on success. This is the equivalent of the Python statement o.attr_name = v
.
If v is NULL
, the attribute is deleted, however this feature is deprecated in favour of using PyObject_DelAttr()
.
PyObject_SetAttrString
Set the value of the attribute named attr_name, for object o, to the value v. Raise an exception and return -1
on failure; return 0
on success. This is the equivalent of the Python statement o.attr_name = v
.
If v is NULL
, the attribute is deleted, however this feature is deprecated in favour of using PyObject_DelAttrString()
.
PyObject_GenericSetAttr
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 an AttributeError
is raised and -1
is returned.
PyObject_DelAttr
Delete attribute named attr_name, for object o. Returns -1
on failure. This is the equivalent of the Python statement del o.attr_name
.
PyObject_DelAttrString
Delete attribute named attr_name, for object o. Returns -1
on failure. This is the equivalent of the Python statement del o.attr_name
.
PyObject_GenericGetDict
A generic implementation for the getter of a __dict__
descriptor. It creates the dictionary if necessary.
New in version 3.3.
PyObject_GenericSetDict
A generic implementation for the setter of a __dict__
descriptor. This implementation does not allow the dictionary to be deleted.
New in version 3.3.
PyObject_RichCompare
Compare the values of o1 and o2 using the operation specified by opid, which must be one of Py_LT
, Py_LE
, Py_EQ
, Py_NE
, Py_GT
, or Py_GE
, corresponding to <
, <=
, ==
, !=
, >
, or >=
respectively. This is the equivalent of the Python expression o1 op o2
, where op
is the operator corresponding to opid. Returns the value of the comparison on success, or NULL
on failure.
PyObject_RichCompareBool
Compare the values of o1 and o2 using the operation specified by opid, which must be one of Py_LT
, Py_LE
, Py_EQ
, Py_NE
, Py_GT
, or Py_GE
, corresponding to <
, <=
, ==
, !=
, >
, or >=
respectively. Returns -1
on error, 0
if the result is false, 1
otherwise. This is the equivalent of the Python expression o1 op o2
, where op
is the operator corresponding to opid.
Note
If o1 and o2 are the same object, PyObject_RichCompareBool()
will always return 1
for Py_EQ
and 0
for Py_NE
.
PyObject_Repr
Compute a string representation of object o. Returns the string representation on success, NULL
on failure. This is the equivalent of the Python expression repr(o)
. Called by the repr()
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_ASCII
As PyObject_Repr()
, compute a string representation of object o, but escape the non-ASCII characters in the string returned by PyObject_Repr()
with \x
, \u
or \U
escapes. This generates a string similar to that returned by PyObject_Repr()
in Python 2. Called by the ascii()
built-in function.
PyObject_Str
Compute a string representation of object o. Returns the string representation on success, NULL
on failure. This is the equivalent of the Python expression str(o)
. Called by the str()
built-in function and, therefore, by the print()
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_Bytes
Compute a bytes representation of object o. NULL
is returned on failure and a bytes object on success. This is equivalent to the Python expression bytes(o)
, when o is not an integer. Unlike bytes(o)
, a TypeError is raised when o is an integer instead of a zero-initialized bytes object.
PyObject_IsSubclass
Return 1
if the class derived is identical to or derived from the class cls, otherwise return 0
. In case of an error, return -1
.
If cls is a tuple, the check will be done against every entry in cls. The result will be 1
when at least one of the checks returns 1
, otherwise it will be 0
.
If cls has a __subclasscheck__()
method, it will be called to determine the subclass status as described in PEP 3119. Otherwise, derived is a subclass of cls if it is a direct or indirect subclass, i.e. contained in cls.__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).
PyObject_IsInstance
Return 1
if inst is an instance of the class cls or a subclass of cls, or 0
if not. On error, returns -1
and sets an exception.
If cls is a tuple, the check will be done against every entry in cls. The result will be 1
when at least one of the checks returns 1
, otherwise it will be 0
.
If cls has a __instancecheck__()
method, it will be called to determine the subclass status as described in PEP 3119. Otherwise, inst is an instance of cls if its class is a subclass of cls.
An instance inst can override what is considered its class by having a __class__
attribute.
An object cls can 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).
PyCallable_Check
Determine if the object o is callable. Return 1
if the object is callable and 0
otherwise. This function always succeeds.
PyObject_Call
Call a callable Python object callable, with arguments given by the tuple args, and named arguments given by the dictionary kwargs.
args must not be NULL
, use an empty tuple if no arguments are needed. If no named arguments are needed, kwargs can be NULL
.
Return the result of the call on success, or raise an exception and return NULL
on failure.
This is the equivalent of the Python expression: callable(*args, **kwargs)
.
PyObject_CallObject
Call a callable Python object callable, with arguments given by the tuple args. If no arguments are needed, then args can be NULL
.
Return the result of the call on success, or raise an exception and return NULL
on failure.
This is the equivalent of the Python expression: callable(*args)
.
PyObject_CallFunction
Call a callable Python object callable, with a variable number of C arguments. The C arguments are described using a Py_BuildValue()
style format string. The format can be NULL
, indicating that no arguments are provided.
Return the result of the call on success, or raise an exception and return NULL
on failure.
This is the equivalent of the Python expression: callable(*args)
.
Note that if you only pass PyObject *
args, PyObject_CallFunctionObjArgs()
is a faster alternative.
Changed in version 3.4: The type of format was changed from char *
.
PyObject_CallMethod
Call the method named name of object obj with a variable number of C arguments. The C arguments are described by a Py_BuildValue()
format string that should produce a tuple.
The format can be NULL
, indicating that no arguments are provided.
Return the result of the call on success, or raise an exception and return NULL
on failure.
This is the equivalent of the Python expression: obj.name(arg1, arg2, ...)
.
Note that if you only pass PyObject *
args, PyObject_CallMethodObjArgs()
is a faster alternative.
Changed in version 3.4: The types of name and format were changed from char *
.
PyObject_CallFunctionObjArgs
Call a callable Python object callable, with a variable number of PyObject*
arguments. The arguments are provided as a variable number of parameters followed by NULL
.
Return the result of the call on success, or raise an exception and return NULL
on failure.
This is the equivalent of the Python expression: callable(arg1, arg2, ...)
.
PyObject_CallMethodObjArgs
Calls a method of the Python object obj, where the name of the method is given as a Python string object in name. It is called with a variable number of PyObject*
arguments. The arguments are provided as a variable number of parameters followed by NULL
.
Return the result of the call on success, or raise an exception and return NULL
on failure.
_PyObject_Vectorcall
Call a callable Python object callable, using vectorcall
if possible.
args is a C array with the positional arguments.
nargsf is the number of positional arguments plus optionally the flag PY_VECTORCALL_ARGUMENTS_OFFSET
(see below). To get actual number of arguments, use PyVectorcall_NARGS(nargsf)
.
kwnames can be either NULL
(no keyword arguments) or a tuple of keyword names. In the latter case, the values of the keyword arguments are stored in args after the positional arguments. The number of keyword arguments does not influence nargsf.
kwnames must contain only objects of type str
(not a subclass), and all keys must be unique.
Return the result of the call on success, or raise an exception and return NULL
on failure.
This uses the vectorcall protocol if the callable supports it; otherwise, the arguments are converted to use tp_call
.
Note
This function is provisional and expected to become public in Python 3.9, with a different name and, possibly, changed semantics. If you use the function, plan for updating your code for Python 3.9.
New in version 3.8.
PY_VECTORCALL_ARGUMENTS_OFFSET
If set in a vectorcall nargsf argument, the callee is allowed to temporarily change args[-1]
. In other words, args points to argument 1 (not 0) in the allocated vector. The callee must restore the value of args[-1]
before returning.
Whenever they can do so cheaply (without additional allocation), callers are encouraged to use PY_VECTORCALL_ARGUMENTS_OFFSET
. Doing so will allow callables such as bound methods to make their onward calls (which include a prepended self argument) cheaply.
New in version 3.8.
PyVectorcall_NARGS
Given a vectorcall nargsf argument, return the actual number of arguments. Currently equivalent to nargsf & ~PY_VECTORCALL_ARGUMENTS_OFFSET
.
New in version 3.8.
_PyObject_FastCallDict
Same as _PyObject_Vectorcall()
except that the keyword arguments are passed as a dictionary in kwdict. This may be NULL
if there are no keyword arguments.
For callables supporting vectorcall
, the arguments are internally converted to the vectorcall convention. Therefore, this function adds some overhead compared to _PyObject_Vectorcall()
. It should only be used if the caller already has a dictionary ready to use.
Note
This function is provisional and expected to become public in Python 3.9, with a different name and, possibly, changed semantics. If you use the function, plan for updating your code for Python 3.9.
New in version 3.8.
PyObject_Hash
Compute and return the hash value of an object o. On failure, return -1
. This is the equivalent of the Python expression hash(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.
PyObject_HashNotImplemented
Set a TypeError
indicating that type(o)
is not hashable and return -1
. This function receives special treatment when stored in a tp_hash
slot, allowing a type to explicitly indicate to the interpreter that it is not hashable.
PyObject_IsTrue
Returns 1
if the object o is considered to be true, and 0
otherwise. This is equivalent to the Python expression not not o
. On failure, return -1
.
PyObject_Not
Returns 0
if the object o is considered to be true, and 1
otherwise. This is equivalent to the Python expression not o
. On failure, return -1
.
PyObject_Type
When o is non-NULL
, returns a type object corresponding to the object type of object o. On failure, raises SystemError
and returns NULL
. This is equivalent to the Python expression type(o)
. This function increments the reference count of the return value. There's really no reason to use this function instead of the common expression o->ob_type
, which returns a pointer of type PyTypeObject*
, except when the incremented reference count is needed.
PyObject_TypeCheck
Return true if the object o is of type type or a subtype of type. Both parameters must be non-NULL
.
PyObject_Size
PyObject_Length
Return the length of object o. If the object o provides either the sequence and mapping protocols, the sequence length is returned. On error, -1
is returned. This is the equivalent to the Python expression len(o)
.
PyObject_LengthHint
Return an estimated length for the object o. 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 expression operator.length_hint(o, default)
.
New in version 3.4.
PyObject_GetItem
Return element of o corresponding to the object key or NULL
on failure. This is the equivalent of the Python expression o[key]
.
PyObject_SetItem
Map the object key to the value v. Raise an exception and return -1
on failure; return 0
on success. This is the equivalent of the Python statement o[key] = v
. This function does not steal a reference to v.
PyObject_DelItem
Remove the mapping for the object key from the object o. Return -1
on failure. This is equivalent to the Python statement del o[key]
.
PyObject_Dir
This is equivalent to the Python expression dir(o)
, returning a (possibly empty) list of strings appropriate for the object argument, or NULL
if there was an error. If the argument is NULL
, this is like the Python dir()
, returning the names of the current locals; in this case, if no execution frame is active then NULL
is returned but PyErr_Occurred()
will return false.
PyObject_GetIter
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. Raises TypeError
and returns NULL
if the object cannot be iterated.