9 .. c:function:: int PyObject_Print(PyObject *o, FILE *fp, int flags)
11 Print an object *o*, on file *fp*. Returns ``-1`` on error. The flags argument
12 is used to enable certain printing options. The only option currently supported
13 is :const:`Py_PRINT_RAW`; if given, the :func:`str` of the object is written
14 instead of the :func:`repr`.
17 .. c:function:: int PyObject_HasAttr(PyObject *o, PyObject *attr_name)
19 Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise. This
20 is equivalent to the Python expression ``hasattr(o, attr_name)``. This function
24 .. c:function:: int PyObject_HasAttrString(PyObject *o, const char *attr_name)
26 Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise. This
27 is equivalent to the Python expression ``hasattr(o, attr_name)``. This function
31 .. c:function:: PyObject* PyObject_GetAttr(PyObject *o, PyObject *attr_name)
33 Retrieve an attribute named *attr_name* from object *o*. Returns the attribute
34 value on success, or *NULL* on failure. This is the equivalent of the Python
35 expression ``o.attr_name``.
38 .. c:function:: PyObject* PyObject_GetAttrString(PyObject *o, const char *attr_name)
40 Retrieve an attribute named *attr_name* from object *o*. Returns the attribute
41 value on success, or *NULL* on failure. This is the equivalent of the Python
42 expression ``o.attr_name``.
45 .. c:function:: PyObject* PyObject_GenericGetAttr(PyObject *o, PyObject *name)
47 Generic attribute getter function that is meant to be put into a type
48 object's ``tp_getattro`` slot. It looks for a descriptor in the dictionary
49 of classes in the object's MRO as well as an attribute in the object's
50 :attr:`__dict__` (if present). As outlined in :ref:`descriptors`, data
51 descriptors take preference over instance attributes, while non-data
52 descriptors don't. Otherwise, an :exc:`AttributeError` is raised.
55 .. c:function:: int PyObject_SetAttr(PyObject *o, PyObject *attr_name, PyObject *v)
57 Set the value of the attribute named *attr_name*, for object *o*, to the value
58 *v*. Returns ``-1`` on failure. This is the equivalent of the Python statement
62 .. c:function:: int PyObject_SetAttrString(PyObject *o, const char *attr_name, PyObject *v)
64 Set the value of the attribute named *attr_name*, for object *o*, to the value
65 *v*. Returns ``-1`` on failure. This is the equivalent of the Python statement
69 .. c:function:: int PyObject_GenericSetAttr(PyObject *o, PyObject *name, PyObject *value)
71 Generic attribute setter function that is meant to be put into a type
72 object's ``tp_setattro`` slot. It looks for a data descriptor in the
73 dictionary of classes in the object's MRO, and if found it takes preference
74 over setting the attribute in the instance dictionary. Otherwise, the
75 attribute is set in the object's :attr:`__dict__` (if present). Otherwise,
76 an :exc:`AttributeError` is raised and ``-1`` is returned.
79 .. c:function:: int PyObject_DelAttr(PyObject *o, PyObject *attr_name)
81 Delete attribute named *attr_name*, for object *o*. Returns ``-1`` on failure.
82 This is the equivalent of the Python statement ``del o.attr_name``.
85 .. c:function:: int PyObject_DelAttrString(PyObject *o, const char *attr_name)
87 Delete attribute named *attr_name*, for object *o*. Returns ``-1`` on failure.
88 This is the equivalent of the Python statement ``del o.attr_name``.
91 .. c:function:: PyObject* PyObject_RichCompare(PyObject *o1, PyObject *o2, int opid)
93 Compare the values of *o1* and *o2* using the operation specified by *opid*,
94 which must be one of :const:`Py_LT`, :const:`Py_LE`, :const:`Py_EQ`,
95 :const:`Py_NE`, :const:`Py_GT`, or :const:`Py_GE`, corresponding to ``<``,
96 ``<=``, ``==``, ``!=``, ``>``, or ``>=`` respectively. This is the equivalent of
97 the Python expression ``o1 op o2``, where ``op`` is the operator corresponding
98 to *opid*. Returns the value of the comparison on success, or *NULL* on failure.
101 .. c:function:: int PyObject_RichCompareBool(PyObject *o1, PyObject *o2, int opid)
103 Compare the values of *o1* and *o2* using the operation specified by *opid*,
104 which must be one of :const:`Py_LT`, :const:`Py_LE`, :const:`Py_EQ`,
105 :const:`Py_NE`, :const:`Py_GT`, or :const:`Py_GE`, corresponding to ``<``,
106 ``<=``, ``==``, ``!=``, ``>``, or ``>=`` respectively. Returns ``-1`` on error,
107 ``0`` if the result is false, ``1`` otherwise. This is the equivalent of the
108 Python expression ``o1 op o2``, where ``op`` is the operator corresponding to
112 If *o1* and *o2* are the same object, :c:func:`PyObject_RichCompareBool`
113 will always return ``1`` for :const:`Py_EQ` and ``0`` for :const:`Py_NE`.
115 .. c:function:: int PyObject_Cmp(PyObject *o1, PyObject *o2, int *result)
117 .. index:: builtin: cmp
119 Compare the values of *o1* and *o2* using a routine provided by *o1*, if one
120 exists, otherwise with a routine provided by *o2*. The result of the comparison
121 is returned in *result*. Returns ``-1`` on failure. This is the equivalent of
122 the Python statement ``result = cmp(o1, o2)``.
125 .. c:function:: int PyObject_Compare(PyObject *o1, PyObject *o2)
127 .. index:: builtin: cmp
129 Compare the values of *o1* and *o2* using a routine provided by *o1*, if one
130 exists, otherwise with a routine provided by *o2*. Returns the result of the
131 comparison on success. On error, the value returned is undefined; use
132 :c:func:`PyErr_Occurred` to detect an error. This is equivalent to the Python
133 expression ``cmp(o1, o2)``.
136 .. c:function:: PyObject* PyObject_Repr(PyObject *o)
138 .. index:: builtin: repr
140 Compute a string representation of object *o*. Returns the string
141 representation on success, *NULL* on failure. This is the equivalent of the
142 Python expression ``repr(o)``. Called by the :func:`repr` built-in function and
146 .. c:function:: PyObject* PyObject_Str(PyObject *o)
148 .. index:: builtin: str
150 Compute a string representation of object *o*. Returns the string
151 representation on success, *NULL* on failure. This is the equivalent of the
152 Python expression ``str(o)``. Called by the :func:`str` built-in function and
153 by the :keyword:`print` statement.
156 .. c:function:: PyObject* PyObject_Bytes(PyObject *o)
158 .. index:: builtin: bytes
160 Compute a bytes representation of object *o*. In 2.x, this is just a alias
161 for :c:func:`PyObject_Str`.
164 .. c:function:: PyObject* PyObject_Unicode(PyObject *o)
166 .. index:: builtin: unicode
168 Compute a Unicode string representation of object *o*. Returns the Unicode
169 string representation on success, *NULL* on failure. This is the equivalent of
170 the Python expression ``unicode(o)``. Called by the :func:`unicode` built-in
174 .. c:function:: int PyObject_IsInstance(PyObject *inst, PyObject *cls)
176 Returns ``1`` if *inst* is an instance of the class *cls* or a subclass of
177 *cls*, or ``0`` if not. On error, returns ``-1`` and sets an exception. If
178 *cls* is a type object rather than a class object, :c:func:`PyObject_IsInstance`
179 returns ``1`` if *inst* is of type *cls*. If *cls* is a tuple, the check will
180 be done against every entry in *cls*. The result will be ``1`` when at least one
181 of the checks returns ``1``, otherwise it will be ``0``. If *inst* is not a
182 class instance and *cls* is neither a type object, nor a class object, nor a
183 tuple, *inst* must have a :attr:`__class__` attribute --- the class relationship
184 of the value of that attribute with *cls* will be used to determine the result
187 .. versionadded:: 2.1
189 .. versionchanged:: 2.2
190 Support for a tuple as the second argument added.
192 Subclass determination is done in a fairly straightforward way, but includes a
193 wrinkle that implementors of extensions to the class system may want to be aware
194 of. If :class:`A` and :class:`B` are class objects, :class:`B` is a subclass of
195 :class:`A` if it inherits from :class:`A` either directly or indirectly. If
196 either is not a class object, a more general mechanism is used to determine the
197 class relationship of the two objects. When testing if *B* is a subclass of
198 *A*, if *A* is *B*, :c:func:`PyObject_IsSubclass` returns true. If *A* and *B*
199 are different objects, *B*'s :attr:`__bases__` attribute is searched in a
200 depth-first fashion for *A* --- the presence of the :attr:`__bases__` attribute
201 is considered sufficient for this determination.
204 .. c:function:: int PyObject_IsSubclass(PyObject *derived, PyObject *cls)
206 Returns ``1`` if the class *derived* is identical to or derived from the class
207 *cls*, otherwise returns ``0``. In case of an error, returns ``-1``. If *cls*
208 is a tuple, the check will be done against every entry in *cls*. The result will
209 be ``1`` when at least one of the checks returns ``1``, otherwise it will be
210 ``0``. If either *derived* or *cls* is not an actual class object (or tuple),
211 this function uses the generic algorithm described above.
213 .. versionadded:: 2.1
215 .. versionchanged:: 2.3
216 Older versions of Python did not support a tuple as the second argument.
219 .. c:function:: int PyCallable_Check(PyObject *o)
221 Determine if the object *o* is callable. Return ``1`` if the object is callable
222 and ``0`` otherwise. This function always succeeds.
225 .. c:function:: PyObject* PyObject_Call(PyObject *callable_object, PyObject *args, PyObject *kw)
227 .. index:: builtin: apply
229 Call a callable Python object *callable_object*, with arguments given by the
230 tuple *args*, and named arguments given by the dictionary *kw*. If no named
231 arguments are needed, *kw* may be *NULL*. *args* must not be *NULL*, use an
232 empty tuple if no arguments are needed. Returns the result of the call on
233 success, or *NULL* on failure. This is the equivalent of the Python expression
234 ``apply(callable_object, args, kw)`` or ``callable_object(*args, **kw)``.
236 .. versionadded:: 2.2
239 .. c:function:: PyObject* PyObject_CallObject(PyObject *callable_object, PyObject *args)
241 .. index:: builtin: apply
243 Call a callable Python object *callable_object*, with arguments given by the
244 tuple *args*. If no arguments are needed, then *args* may be *NULL*. Returns
245 the result of the call on success, or *NULL* on failure. This is the equivalent
246 of the Python expression ``apply(callable_object, args)`` or
247 ``callable_object(*args)``.
250 .. c:function:: PyObject* PyObject_CallFunction(PyObject *callable, char *format, ...)
252 .. index:: builtin: apply
254 Call a callable Python object *callable*, with a variable number of C arguments.
255 The C arguments are described using a :c:func:`Py_BuildValue` style format
256 string. The format may be *NULL*, indicating that no arguments are provided.
257 Returns the result of the call on success, or *NULL* on failure. This is the
258 equivalent of the Python expression ``apply(callable, args)`` or
259 ``callable(*args)``. Note that if you only pass :c:type:`PyObject \*` args,
260 :c:func:`PyObject_CallFunctionObjArgs` is a faster alternative.
263 .. c:function:: PyObject* PyObject_CallMethod(PyObject *o, char *method, char *format, ...)
265 Call the method named *method* of object *o* with a variable number of C
266 arguments. The C arguments are described by a :c:func:`Py_BuildValue` format
267 string that should produce a tuple. The format may be *NULL*, indicating that
268 no arguments are provided. Returns the result of the call on success, or *NULL*
269 on failure. This is the equivalent of the Python expression ``o.method(args)``.
270 Note that if you only pass :c:type:`PyObject \*` args,
271 :c:func:`PyObject_CallMethodObjArgs` is a faster alternative.
274 .. c:function:: PyObject* PyObject_CallFunctionObjArgs(PyObject *callable, ..., NULL)
276 Call a callable Python object *callable*, with a variable number of
277 :c:type:`PyObject\*` arguments. The arguments are provided as a variable number
278 of parameters followed by *NULL*. Returns the result of the call on success, or
281 .. versionadded:: 2.2
284 .. c:function:: PyObject* PyObject_CallMethodObjArgs(PyObject *o, PyObject *name, ..., NULL)
286 Calls a method of the object *o*, where the name of the method is given as a
287 Python string object in *name*. It is called with a variable number of
288 :c:type:`PyObject\*` arguments. The arguments are provided as a variable number
289 of parameters followed by *NULL*. Returns the result of the call on success, or
292 .. versionadded:: 2.2
295 .. c:function:: long PyObject_Hash(PyObject *o)
297 .. index:: builtin: hash
299 Compute and return the hash value of an object *o*. On failure, return ``-1``.
300 This is the equivalent of the Python expression ``hash(o)``.
303 .. c:function:: long PyObject_HashNotImplemented(PyObject *o)
305 Set a :exc:`TypeError` indicating that ``type(o)`` is not hashable and return ``-1``.
306 This function receives special treatment when stored in a ``tp_hash`` slot,
307 allowing a type to explicitly indicate to the interpreter that it is not
310 .. versionadded:: 2.6
313 .. c:function:: int PyObject_IsTrue(PyObject *o)
315 Returns ``1`` if the object *o* is considered to be true, and ``0`` otherwise.
316 This is equivalent to the Python expression ``not not o``. On failure, return
320 .. c:function:: int PyObject_Not(PyObject *o)
322 Returns ``0`` if the object *o* is considered to be true, and ``1`` otherwise.
323 This is equivalent to the Python expression ``not o``. On failure, return
327 .. c:function:: PyObject* PyObject_Type(PyObject *o)
329 .. index:: builtin: type
331 When *o* is non-*NULL*, returns a type object corresponding to the object type
332 of object *o*. On failure, raises :exc:`SystemError` and returns *NULL*. This
333 is equivalent to the Python expression ``type(o)``. This function increments the
334 reference count of the return value. There's really no reason to use this
335 function instead of the common expression ``o->ob_type``, which returns a
336 pointer of type :c:type:`PyTypeObject\*`, except when the incremented reference
340 .. c:function:: int PyObject_TypeCheck(PyObject *o, PyTypeObject *type)
342 Return true if the object *o* is of type *type* or a subtype of *type*. Both
343 parameters must be non-*NULL*.
345 .. versionadded:: 2.2
348 .. c:function:: Py_ssize_t PyObject_Length(PyObject *o)
349 Py_ssize_t PyObject_Size(PyObject *o)
351 .. index:: builtin: len
353 Return the length of object *o*. If the object *o* provides either the sequence
354 and mapping protocols, the sequence length is returned. On error, ``-1`` is
355 returned. This is the equivalent to the Python expression ``len(o)``.
357 .. versionchanged:: 2.5
358 These functions returned an :c:type:`int` type. This might require
359 changes in your code for properly supporting 64-bit systems.
362 .. c:function:: PyObject* PyObject_GetItem(PyObject *o, PyObject *key)
364 Return element of *o* corresponding to the object *key* or *NULL* on failure.
365 This is the equivalent of the Python expression ``o[key]``.
368 .. c:function:: int PyObject_SetItem(PyObject *o, PyObject *key, PyObject *v)
370 Map the object *key* to the value *v*. Returns ``-1`` on failure. This is the
371 equivalent of the Python statement ``o[key] = v``.
374 .. c:function:: int PyObject_DelItem(PyObject *o, PyObject *key)
376 Delete the mapping for *key* from *o*. Returns ``-1`` on failure. This is the
377 equivalent of the Python statement ``del o[key]``.
380 .. c:function:: int PyObject_AsFileDescriptor(PyObject *o)
382 Derives a file descriptor from a Python object. If the object is an integer or
383 long integer, its value is returned. If not, the object's :meth:`fileno` method
384 is called if it exists; the method must return an integer or long integer, which
385 is returned as the file descriptor value. Returns ``-1`` on failure.
388 .. c:function:: PyObject* PyObject_Dir(PyObject *o)
390 This is equivalent to the Python expression ``dir(o)``, returning a (possibly
391 empty) list of strings appropriate for the object argument, or *NULL* if there
392 was an error. If the argument is *NULL*, this is like the Python ``dir()``,
393 returning the names of the current locals; in this case, if no execution frame
394 is active then *NULL* is returned but :c:func:`PyErr_Occurred` will return false.
397 .. c:function:: PyObject* PyObject_GetIter(PyObject *o)
399 This is equivalent to the Python expression ``iter(o)``. It returns a new
400 iterator for the object argument, or the object itself if the object is already
401 an iterator. Raises :exc:`TypeError` and returns *NULL* if the object cannot be