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Object Protocol
-
int
PyObject_Print
( PyObject *o, FILE *fp, int flags ) -
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 isPy_PRINT_RAW
; if given, thestr()
of the object is written instead of therepr()
.
-
int
PyObject_HasAttr
( PyObject *o, PyObject *attr_name ) -
Returns
1
if o has the attribute attr_name, and0
otherwise. This is equivalent to the Python expressionhasattr(o, attr_name)
. This function always succeeds.
-
int
PyObject_HasAttrString
( PyObject *o, const char *attr_name ) -
Returns
1
if o has the attribute attr_name, and0
otherwise. This is equivalent to the Python expressionhasattr(o, attr_name)
. This function always succeeds.
- PyObject*
PyObject_GetAttr
( PyObject *o, PyObject *attr_name ) - Return value: New reference.
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*
PyObject_GetAttrString
( PyObject *o, const char *attr_name ) - Return value: New reference.
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*
PyObject_GenericGetAttr
( PyObject *o, PyObject *name ) -
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, anAttributeError
is raised.
-
int
PyObject_SetAttr
( PyObject *o, PyObject *attr_name, PyObject *v ) -
Set the value of the attribute named attr_name, for object o, 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
.If v is NULL, the attribute is deleted, however this feature is deprecated in favour of using
PyObject_DelAttr()
.
-
int
PyObject_SetAttrString
( PyObject *o, const char *attr_name, PyObject *v ) -
Set the value of the attribute named attr_name, for object o, 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
.If v is NULL, the attribute is deleted, however this feature is deprecated in favour of using
PyObject_DelAttrString()
.
-
int
PyObject_GenericSetAttr
( PyObject *o, PyObject *name, PyObject *value ) -
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.
-
int
PyObject_DelAttr
( PyObject *o, PyObject *attr_name ) -
Delete attribute named attr_name, for object o. Returns
-1
on failure. This is the equivalent of the Python statementdel o.attr_name
.
-
int
PyObject_DelAttrString
( PyObject *o, const char *attr_name ) -
Delete attribute named attr_name, for object o. Returns
-1
on failure. This is the equivalent of the Python statementdel o.attr_name
.
- PyObject*
PyObject_RichCompare
( PyObject *o1, PyObject *o2, int opid ) - Return value: New reference.
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
, orPy_GE
, corresponding to<
,<=
,==
,!=
,>
, or>=
respectively. This is the equivalent of the Python expressiono1 op o2
, whereop
is the operator corresponding to opid. Returns the value of the comparison on success, or NULL on failure.
-
int
PyObject_RichCompareBool
( PyObject *o1, PyObject *o2, int opid ) -
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
, orPy_GE
, corresponding to<
,<=
,==
,!=
,>
, or>=
respectively. Returns-1
on error,0
if the result is false,1
otherwise. This is the equivalent of the Python expressiono1 op o2
, whereop
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
.
-
int
PyObject_Cmp
( PyObject *o1, PyObject *o2, int *result ) -
Compare the values of o1 and o2 using a routine provided by o1, if one exists, otherwise with a routine provided by o2. The result of the comparison is returned in result. Returns
-1
on failure. This is the equivalent of the Python statementresult = cmp(o1, o2)
.
-
int
PyObject_Compare
( PyObject *o1, PyObject *o2 ) -
Compare the values of o1 and o2 using a routine provided by o1, if one exists, otherwise with a routine provided by o2. Returns the result of the comparison on success. On error, the value returned is undefined; use
PyErr_Occurred()
to detect an error. This is equivalent to the Python expressioncmp(o1, o2)
.
- PyObject*
PyObject_Repr
( PyObject *o ) - Return value: New reference.
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 therepr()
built-in function and by reverse quotes.
- PyObject*
PyObject_Str
( PyObject *o ) - Return value: New reference.
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 thestr()
built-in function and by theprint
statement.
- PyObject*
PyObject_Bytes
( PyObject *o ) -
Compute a bytes representation of object o. In 2.x, this is just an alias for
PyObject_Str()
.
- PyObject*
PyObject_Unicode
( PyObject *o ) - Return value: New reference.
Compute a Unicode string representation of object o. Returns the Unicode string representation on success, NULL on failure. This is the equivalent of the Python expression
unicode(o)
. Called by theunicode()
built-in function.
-
int
PyObject_IsInstance
( PyObject *inst, PyObject *cls ) -
Returns
1
if inst is an instance of the class cls or a subclass of cls, or0
if not. On error, returns-1
and sets an exception. If cls is a type object rather than a class object,PyObject_IsInstance()
returns1
if inst is of type cls. If cls is a tuple, the check will be done against every entry in cls. The result will be1
when at least one of the checks returns1
, otherwise it will be0
. If inst is not a class instance and cls is neither a type object, nor a class object, nor a tuple, inst must have a__class__
attribute — the class relationship of the value of that attribute with cls will be used to determine the result of this function.New in version 2.1.
Changed in version 2.2: Support for a tuple as the second argument added.
Subclass determination is done in a fairly straightforward way, but includes a wrinkle that implementors of extensions to the class system may want to be aware of. If A
and B
are class objects, B
is a subclass of A
if it inherits from A
either directly or indirectly. If either is not a class object, a more general mechanism is used to determine the class relationship of the two objects. When testing if B is a subclass of A, if A is B, PyObject_IsSubclass()
returns true. If A and B are different objects, B’s __bases__
attribute is searched in a depth-first fashion for A — the presence of the __bases__
attribute is considered sufficient for this determination.
-
int
PyObject_IsSubclass
( PyObject *derived, PyObject *cls ) -
Returns
1
if the class derived is identical to or derived from the class cls, otherwise returns0
. In case of an error, returns-1
. If cls is a tuple, the check will be done against every entry in cls. The result will be1
when at least one of the checks returns1
, otherwise it will be0
. If either derived or cls is not an actual class object (or tuple), this function uses the generic algorithm described above.New in version 2.1.
Changed in version 2.3: Older versions of Python did not support a tuple as the second argument.
-
int
PyCallable_Check
( PyObject *o ) -
Determine if the object o is callable. Return
1
if the object is callable and0
otherwise. This function always succeeds.
- PyObject*
PyObject_Call
( PyObject *callable_object, PyObject *args, PyObject *kw ) - Return value: New reference.
Call a callable Python object callable_object, with arguments given by the tuple args, and named arguments given by the dictionary kw. If no named arguments are needed, kw may be NULL. args must not be NULL, use an empty tuple if no arguments are needed. Returns the result of the call on success, or NULL on failure. This is the equivalent of the Python expression
apply(callable_object, args, kw)
orcallable_object(*args, **kw)
.New in version 2.2.
- PyObject*
PyObject_CallObject
( PyObject *callable_object, PyObject *args ) - Return value: New reference.
Call a callable Python object callable_object, with arguments given by the tuple args. If no arguments are needed, then args may be NULL. Returns the result of the call on success, or NULL on failure. This is the equivalent of the Python expression
apply(callable_object, args)
orcallable_object(*args)
.
- PyObject*
PyObject_CallFunction
( PyObject *callable, char *format, ... ) - Return value: New reference.
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 may be NULL, indicating that no arguments are provided. Returns the result of the call on success, or NULL on failure. This is the equivalent of the Python expressionapply(callable, args)
orcallable(*args)
. Note that if you only passPyObject *
args,PyObject_CallFunctionObjArgs()
is a faster alternative.
- PyObject*
PyObject_CallMethod
( PyObject *o, char *method, char *format, ... ) - Return value: New reference.
Call the method named method of object o 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 may be NULL, indicating that no arguments are provided. Returns the result of the call on success, or NULL on failure. This is the equivalent of the Python expressiono.method(args)
. Note that if you only passPyObject *
args,PyObject_CallMethodObjArgs()
is a faster alternative.
- PyObject*
PyObject_CallFunctionObjArgs
( PyObject *callable, ..., NULL ) - Return value: New reference.
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. Returns the result of the call on success, or NULL on failure.New in version 2.2.
- PyObject*
PyObject_CallMethodObjArgs
( PyObject *o, PyObject *name, ..., NULL ) - Return value: New reference.
Calls a method of the object o, 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. Returns the result of the call on success, or NULL on failure.New in version 2.2.
-
long
PyObject_Hash
( PyObject *o ) -
Compute and return the hash value of an object o. On failure, return
-1
. This is the equivalent of the Python expressionhash(o)
.
-
long
PyObject_HashNotImplemented
( PyObject *o ) -
Set a
TypeError
indicating thattype(o)
is not hashable 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 not hashable.New in version 2.6.
-
int
PyObject_IsTrue
( PyObject *o ) -
Returns
1
if the object o is considered to be true, and0
otherwise. This is equivalent to the Python expressionnot not o
. On failure, return-1
.
-
int
PyObject_Not
( PyObject *o ) -
Returns
0
if the object o is considered to be true, and1
otherwise. This is equivalent to the Python expressionnot o
. On failure, return-1
.
- PyObject*
PyObject_Type
( PyObject *o ) - Return value: New reference.
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 expressiontype(o)
. This function increments the reference count of the return value. There’s really no reason to use this function instead of the common expressiono->ob_type
, which returns a pointer of typePyTypeObject*
, except when the incremented reference count is needed.
-
int
PyObject_TypeCheck
( PyObject *o, PyTypeObject *type ) -
Return true if the object o is of type type or a subtype of type. Both parameters must be non-NULL.
New in version 2.2.
-
Py_ssize_t
PyObject_Length
( PyObject *o ) -
Py_ssize_t
PyObject_Size
( PyObject *o ) -
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 expressionlen(o)
.Changed in version 2.5: These functions returned an
int
type. This might require changes in your code for properly supporting 64-bit systems.
- PyObject*
PyObject_GetItem
( PyObject *o, PyObject *key ) - Return value: New reference.
Return element of o corresponding to the object key or NULL on failure. This is the equivalent of the Python expression
o[key]
.
-
int
PyObject_SetItem
( PyObject *o, PyObject *key, PyObject *v ) -
Map the object key to the value v. Raise an exception and return
-1
on failure; return0
on success. This is the equivalent of the Python statemento[key] = v
.
-
int
PyObject_DelItem
( PyObject *o, PyObject *key ) -
Delete the mapping for key from o. Returns
-1
on failure. This is the equivalent of the Python statementdel o[key]
.
-
int
PyObject_AsFileDescriptor
( PyObject *o ) -
Derives a file descriptor from a Python object. If the object is an integer or long integer, its value is returned. If not, the object’s
fileno()
method is called if it exists; the method must return an integer or long integer, which is returned as the file descriptor value. Returns-1
on failure.
- PyObject*
PyObject_Dir
( PyObject *o ) - Return value: New reference.
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 Pythondir()
, returning the names of the current locals; in this case, if no execution frame is active then NULL is returned butPyErr_Occurred()
will return false.
- PyObject*
PyObject_GetIter
( PyObject *o ) - Return value: New reference.
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 returns NULL if the object cannot be iterated.