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diff --git a/Doc/c-api/abstract.rst b/Doc/c-api/abstract.rst index c616561..66426f7 100644 --- a/Doc/c-api/abstract.rst +++ b/Doc/c-api/abstract.rst @@ -1,6 +1,5 @@ .. highlightlang:: c - .. _abstract: ********************** @@ -16,928 +15,11 @@ It is not possible to use these functions on objects that are not properly initialized, such as a list object that has been created by :cfunc:`PyList_New`, but whose items have not been set to some non-\ ``NULL`` value yet. +.. toctree:: -.. _object: - -Object Protocol -=============== - - -.. cfunction:: 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 - is :const:`Py_PRINT_RAW`; if given, the :func:`str` of the object is written - instead of the :func:`repr`. - - -.. cfunction:: int PyObject_HasAttr(PyObject *o, PyObject *attr_name) - - 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. - - -.. cfunction:: int PyObject_HasAttrString(PyObject *o, const char *attr_name) - - 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. - - -.. cfunction:: PyObject* PyObject_GetAttr(PyObject *o, PyObject *attr_name) - - 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``. - - -.. cfunction:: PyObject* PyObject_GetAttrString(PyObject *o, const char *attr_name) - - 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``. - - -.. cfunction:: 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*. Returns ``-1`` on failure. This is the equivalent of the Python statement - ``o.attr_name = v``. - - -.. cfunction:: 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*. Returns ``-1`` on failure. This is the equivalent of the Python statement - ``o.attr_name = v``. - - -.. cfunction:: 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 statement ``del o.attr_name``. - - -.. cfunction:: 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 statement ``del o.attr_name``. - - -.. cfunction:: PyObject* PyObject_RichCompare(PyObject *o1, PyObject *o2, int opid) - - Compare the values of *o1* and *o2* using the operation specified by *opid*, - which must be one of :const:`Py_LT`, :const:`Py_LE`, :const:`Py_EQ`, - :const:`Py_NE`, :const:`Py_GT`, or :const:`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. - - -.. cfunction:: 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 :const:`Py_LT`, :const:`Py_LE`, :const:`Py_EQ`, - :const:`Py_NE`, :const:`Py_GT`, or :const:`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*. - - -.. cfunction:: int PyObject_Cmp(PyObject *o1, PyObject *o2, int *result) - - .. index:: builtin: cmp - - 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 statement ``result = cmp(o1, o2)``. - - -.. cfunction:: int PyObject_Compare(PyObject *o1, PyObject *o2) - - .. index:: builtin: cmp - - 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 - :cfunc:`PyErr_Occurred` to detect an error. This is equivalent to the Python - expression ``cmp(o1, o2)``. - - -.. cfunction:: PyObject* PyObject_Repr(PyObject *o) - - .. index:: builtin: 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 :func:`repr` built-in function and - by reverse quotes. - - -.. cfunction:: PyObject* PyObject_Str(PyObject *o) - - .. index:: builtin: 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 :func:`str` built-in function - and, therefore, by the :func:`print` function. - - -.. cfunction:: PyObject* PyObject_Unicode(PyObject *o) - - .. index:: builtin: unicode - - 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 the :func:`unicode` built-in - function. - - -.. cfunction:: int PyObject_IsInstance(PyObject *inst, PyObject *cls) - - Returns ``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 type object rather than a class object, :cfunc:`PyObject_IsInstance` - returns ``1`` if *inst* is of type *cls*. 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 *inst* is not a - class instance and *cls* is neither a type object, nor a class object, nor a - tuple, *inst* must have a :attr:`__class__` attribute --- the class relationship - of the value of that attribute with *cls* will be used to determine the result - of this function. - - -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 :class:`A` and :class:`B` are class objects, :class:`B` is a subclass of -:class:`A` if it inherits from :class:`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*, :cfunc:`PyObject_IsSubclass` returns true. If *A* and *B* -are different objects, *B*'s :attr:`__bases__` attribute is searched in a -depth-first fashion for *A* --- the presence of the :attr:`__bases__` attribute -is considered sufficient for this determination. - - -.. cfunction:: int PyObject_IsSubclass(PyObject *derived, PyObject *cls) - - Returns ``1`` if the class *derived* is identical to or derived from the class - *cls*, otherwise returns ``0``. 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 - be ``1`` when at least one of the checks returns ``1``, otherwise it will be - ``0``. If either *derived* or *cls* is not an actual class object (or tuple), - this function uses the generic algorithm described above. - - -.. cfunction:: int PyCallable_Check(PyObject *o) - - Determine if the object *o* is callable. Return ``1`` if the object is callable - and ``0`` otherwise. This function always succeeds. - - -.. cfunction:: PyObject* PyObject_Call(PyObject *callable_object, PyObject *args, PyObject *kw) - - 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 - ``callable_object(*args, **kw)``. - - -.. cfunction:: PyObject* PyObject_CallObject(PyObject *callable_object, PyObject *args) - - 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 ``callable_object(*args)``. - - -.. cfunction:: PyObject* PyObject_CallFunction(PyObject *callable, char *format, ...) - - Call a callable Python object *callable*, with a variable number of C arguments. - The C arguments are described using a :cfunc:`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 expression ``callable(*args)``. Note that if you only - pass :ctype:`PyObject \*` args, :cfunc:`PyObject_CallFunctionObjArgs` is a - faster alternative. - - -.. cfunction:: PyObject* PyObject_CallMethod(PyObject *o, char *method, char *format, ...) - - Call the method named *method* of object *o* with a variable number of C - arguments. The C arguments are described by a :cfunc:`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 expression ``o.method(args)``. - Note that if you only pass :ctype:`PyObject \*` args, - :cfunc:`PyObject_CallMethodObjArgs` is a faster alternative. - - -.. cfunction:: PyObject* PyObject_CallFunctionObjArgs(PyObject *callable, ..., NULL) - - Call a callable Python object *callable*, with a variable number of - :ctype:`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. - - -.. cfunction:: PyObject* PyObject_CallMethodObjArgs(PyObject *o, PyObject *name, ..., NULL) - - 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 - :ctype:`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. - - -.. cfunction:: long PyObject_Hash(PyObject *o) - - .. index:: builtin: 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)``. - - -.. cfunction:: int PyObject_IsTrue(PyObject *o) - - 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``. - - -.. cfunction:: int PyObject_Not(PyObject *o) - - 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``. - - -.. cfunction:: PyObject* PyObject_Type(PyObject *o) - - .. index:: builtin: type - - When *o* is non-*NULL*, returns a type object corresponding to the object type - of object *o*. On failure, raises :exc:`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 :ctype:`PyTypeObject\*`, except when the incremented reference - count is needed. - - -.. cfunction:: 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*. - - -.. cfunction:: Py_ssize_t PyObject_Length(PyObject *o) - Py_ssize_t PyObject_Size(PyObject *o) - - .. index:: builtin: len - - 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)``. - - -.. cfunction:: PyObject* PyObject_GetItem(PyObject *o, PyObject *key) - - Return element of *o* corresponding to the object *key* or *NULL* on failure. - This is the equivalent of the Python expression ``o[key]``. - - -.. cfunction:: int PyObject_SetItem(PyObject *o, PyObject *key, PyObject *v) - - Map the object *key* to the value *v*. Returns ``-1`` on failure. This is the - equivalent of the Python statement ``o[key] = v``. - - -.. cfunction:: 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 statement ``del o[key]``. - - -.. cfunction:: PyObject* PyObject_Dir(PyObject *o) - - 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 :cfunc:`PyErr_Occurred` will return false. - - -.. cfunction:: PyObject* PyObject_GetIter(PyObject *o) - - 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 :exc:`TypeError` and returns *NULL* if the object cannot be - iterated. - - -.. _number: - -Number Protocol -=============== - - -.. cfunction:: int PyNumber_Check(PyObject *o) - - Returns ``1`` if the object *o* provides numeric protocols, and false otherwise. - This function always succeeds. - - -.. cfunction:: PyObject* PyNumber_Add(PyObject *o1, PyObject *o2) - - Returns the result of adding *o1* and *o2*, or *NULL* on failure. This is the - equivalent of the Python expression ``o1 + o2``. - - -.. cfunction:: PyObject* PyNumber_Subtract(PyObject *o1, PyObject *o2) - - Returns the result of subtracting *o2* from *o1*, or *NULL* on failure. This is - the equivalent of the Python expression ``o1 - o2``. - - -.. cfunction:: PyObject* PyNumber_Multiply(PyObject *o1, PyObject *o2) - - Returns the result of multiplying *o1* and *o2*, or *NULL* on failure. This is - the equivalent of the Python expression ``o1 * o2``. - - -.. cfunction:: PyObject* PyNumber_Divide(PyObject *o1, PyObject *o2) - - Returns the result of dividing *o1* by *o2*, or *NULL* on failure. This is the - equivalent of the Python expression ``o1 / o2``. - - -.. cfunction:: PyObject* PyNumber_FloorDivide(PyObject *o1, PyObject *o2) - - Return the floor of *o1* divided by *o2*, or *NULL* on failure. This is - equivalent to the "classic" division of integers. - - -.. cfunction:: PyObject* PyNumber_TrueDivide(PyObject *o1, PyObject *o2) - - Return a reasonable approximation for the mathematical value of *o1* divided by - *o2*, or *NULL* on failure. The return value is "approximate" because binary - floating point numbers are approximate; it is not possible to represent all real - numbers in base two. This function can return a floating point value when - passed two integers. - - -.. cfunction:: PyObject* PyNumber_Remainder(PyObject *o1, PyObject *o2) - - Returns the remainder of dividing *o1* by *o2*, or *NULL* on failure. This is - the equivalent of the Python expression ``o1 % o2``. - - -.. cfunction:: PyObject* PyNumber_Divmod(PyObject *o1, PyObject *o2) - - .. index:: builtin: divmod - - See the built-in function :func:`divmod`. Returns *NULL* on failure. This is - the equivalent of the Python expression ``divmod(o1, o2)``. - - -.. cfunction:: PyObject* PyNumber_Power(PyObject *o1, PyObject *o2, PyObject *o3) - - .. index:: builtin: pow - - See the built-in function :func:`pow`. Returns *NULL* on failure. This is the - equivalent of the Python expression ``pow(o1, o2, o3)``, where *o3* is optional. - If *o3* is to be ignored, pass :cdata:`Py_None` in its place (passing *NULL* for - *o3* would cause an illegal memory access). - - -.. cfunction:: PyObject* PyNumber_Negative(PyObject *o) - - Returns the negation of *o* on success, or *NULL* on failure. This is the - equivalent of the Python expression ``-o``. - - -.. cfunction:: PyObject* PyNumber_Positive(PyObject *o) - - Returns *o* on success, or *NULL* on failure. This is the equivalent of the - Python expression ``+o``. - - -.. cfunction:: PyObject* PyNumber_Absolute(PyObject *o) - - .. index:: builtin: abs - - Returns the absolute value of *o*, or *NULL* on failure. This is the equivalent - of the Python expression ``abs(o)``. - - -.. cfunction:: PyObject* PyNumber_Invert(PyObject *o) - - Returns the bitwise negation of *o* on success, or *NULL* on failure. This is - the equivalent of the Python expression ``~o``. - - -.. cfunction:: PyObject* PyNumber_Lshift(PyObject *o1, PyObject *o2) - - Returns the result of left shifting *o1* by *o2* on success, or *NULL* on - failure. This is the equivalent of the Python expression ``o1 << o2``. - - -.. cfunction:: PyObject* PyNumber_Rshift(PyObject *o1, PyObject *o2) - - Returns the result of right shifting *o1* by *o2* on success, or *NULL* on - failure. This is the equivalent of the Python expression ``o1 >> o2``. - - -.. cfunction:: PyObject* PyNumber_And(PyObject *o1, PyObject *o2) - - Returns the "bitwise and" of *o1* and *o2* on success and *NULL* on failure. - This is the equivalent of the Python expression ``o1 & o2``. - - -.. cfunction:: PyObject* PyNumber_Xor(PyObject *o1, PyObject *o2) - - Returns the "bitwise exclusive or" of *o1* by *o2* on success, or *NULL* on - failure. This is the equivalent of the Python expression ``o1 ^ o2``. - - -.. cfunction:: PyObject* PyNumber_Or(PyObject *o1, PyObject *o2) - - Returns the "bitwise or" of *o1* and *o2* on success, or *NULL* on failure. - This is the equivalent of the Python expression ``o1 | o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceAdd(PyObject *o1, PyObject *o2) - - Returns the result of adding *o1* and *o2*, or *NULL* on failure. The operation - is done *in-place* when *o1* supports it. This is the equivalent of the Python - statement ``o1 += o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceSubtract(PyObject *o1, PyObject *o2) - - Returns the result of subtracting *o2* from *o1*, or *NULL* on failure. The - operation is done *in-place* when *o1* supports it. This is the equivalent of - the Python statement ``o1 -= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceMultiply(PyObject *o1, PyObject *o2) - - Returns the result of multiplying *o1* and *o2*, or *NULL* on failure. The - operation is done *in-place* when *o1* supports it. This is the equivalent of - the Python statement ``o1 *= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceDivide(PyObject *o1, PyObject *o2) - - Returns the result of dividing *o1* by *o2*, or *NULL* on failure. The - operation is done *in-place* when *o1* supports it. This is the equivalent of - the Python statement ``o1 /= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceFloorDivide(PyObject *o1, PyObject *o2) - - Returns the mathematical floor of dividing *o1* by *o2*, or *NULL* on failure. - The operation is done *in-place* when *o1* supports it. This is the equivalent - of the Python statement ``o1 //= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceTrueDivide(PyObject *o1, PyObject *o2) - - Return a reasonable approximation for the mathematical value of *o1* divided by - *o2*, or *NULL* on failure. The return value is "approximate" because binary - floating point numbers are approximate; it is not possible to represent all real - numbers in base two. This function can return a floating point value when - passed two integers. The operation is done *in-place* when *o1* supports it. - - -.. cfunction:: PyObject* PyNumber_InPlaceRemainder(PyObject *o1, PyObject *o2) - - Returns the remainder of dividing *o1* by *o2*, or *NULL* on failure. The - operation is done *in-place* when *o1* supports it. This is the equivalent of - the Python statement ``o1 %= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlacePower(PyObject *o1, PyObject *o2, PyObject *o3) - - .. index:: builtin: pow - - See the built-in function :func:`pow`. Returns *NULL* on failure. The operation - is done *in-place* when *o1* supports it. This is the equivalent of the Python - statement ``o1 **= o2`` when o3 is :cdata:`Py_None`, or an in-place variant of - ``pow(o1, o2, o3)`` otherwise. If *o3* is to be ignored, pass :cdata:`Py_None` - in its place (passing *NULL* for *o3* would cause an illegal memory access). - - -.. cfunction:: PyObject* PyNumber_InPlaceLshift(PyObject *o1, PyObject *o2) - - Returns the result of left shifting *o1* by *o2* on success, or *NULL* on - failure. The operation is done *in-place* when *o1* supports it. This is the - equivalent of the Python statement ``o1 <<= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceRshift(PyObject *o1, PyObject *o2) - - Returns the result of right shifting *o1* by *o2* on success, or *NULL* on - failure. The operation is done *in-place* when *o1* supports it. This is the - equivalent of the Python statement ``o1 >>= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceAnd(PyObject *o1, PyObject *o2) - - Returns the "bitwise and" of *o1* and *o2* on success and *NULL* on failure. The - operation is done *in-place* when *o1* supports it. This is the equivalent of - the Python statement ``o1 &= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceXor(PyObject *o1, PyObject *o2) - - Returns the "bitwise exclusive or" of *o1* by *o2* on success, or *NULL* on - failure. The operation is done *in-place* when *o1* supports it. This is the - equivalent of the Python statement ``o1 ^= o2``. - - -.. cfunction:: PyObject* PyNumber_InPlaceOr(PyObject *o1, PyObject *o2) - - Returns the "bitwise or" of *o1* and *o2* on success, or *NULL* on failure. The - operation is done *in-place* when *o1* supports it. This is the equivalent of - the Python statement ``o1 |= o2``. - - -.. cfunction:: PyObject* PyNumber_Int(PyObject *o) - - .. index:: builtin: int - - Returns the *o* converted to an integer object on success, or *NULL* on failure. - If the argument is outside the integer range a long object will be returned - instead. This is the equivalent of the Python expression ``int(o)``. - - -.. cfunction:: PyObject* PyNumber_Long(PyObject *o) - - .. index:: builtin: long - - Returns the *o* converted to an integer object on success, or *NULL* on - failure. This is the equivalent of the Python expression ``long(o)``. - - -.. cfunction:: PyObject* PyNumber_Float(PyObject *o) - - .. index:: builtin: float - - Returns the *o* converted to a float object on success, or *NULL* on failure. - This is the equivalent of the Python expression ``float(o)``. - - -.. cfunction:: PyObject* PyNumber_Index(PyObject *o) - - Returns the *o* converted to a Python int or long on success or *NULL* with a - TypeError exception raised on failure. - - -.. cfunction:: Py_ssize_t PyNumber_AsSsize_t(PyObject *o, PyObject *exc) - - Returns *o* converted to a Py_ssize_t value if *o* can be interpreted as an - integer. If *o* can be converted to a Python int or long but the attempt to - convert to a Py_ssize_t value would raise an :exc:`OverflowError`, then the - *exc* argument is the type of exception that will be raised (usually - :exc:`IndexError` or :exc:`OverflowError`). If *exc* is *NULL*, then the - exception is cleared and the value is clipped to *PY_SSIZE_T_MIN* for a negative - integer or *PY_SSIZE_T_MAX* for a positive integer. - - -.. cfunction:: int PyIndex_Check(PyObject *o) - - Returns True if *o* is an index integer (has the nb_index slot of the - tp_as_number structure filled in). - - -.. _sequence: - -Sequence Protocol -================= - - -.. cfunction:: int PySequence_Check(PyObject *o) - - Return ``1`` if the object provides sequence protocol, and ``0`` otherwise. - This function always succeeds. - - -.. cfunction:: Py_ssize_t PySequence_Size(PyObject *o) - - .. index:: builtin: len - - Returns the number of objects in sequence *o* on success, and ``-1`` on failure. - For objects that do not provide sequence protocol, this is equivalent to the - Python expression ``len(o)``. - - -.. cfunction:: Py_ssize_t PySequence_Length(PyObject *o) - - Alternate name for :cfunc:`PySequence_Size`. - - -.. cfunction:: PyObject* PySequence_Concat(PyObject *o1, PyObject *o2) - - Return the concatenation of *o1* and *o2* on success, and *NULL* on failure. - This is the equivalent of the Python expression ``o1 + o2``. - - -.. cfunction:: PyObject* PySequence_Repeat(PyObject *o, Py_ssize_t count) - - Return the result of repeating sequence object *o* *count* times, or *NULL* on - failure. This is the equivalent of the Python expression ``o * count``. - - -.. cfunction:: PyObject* PySequence_InPlaceConcat(PyObject *o1, PyObject *o2) - - Return the concatenation of *o1* and *o2* on success, and *NULL* on failure. - The operation is done *in-place* when *o1* supports it. This is the equivalent - of the Python expression ``o1 += o2``. - - -.. cfunction:: PyObject* PySequence_InPlaceRepeat(PyObject *o, Py_ssize_t count) - - Return the result of repeating sequence object *o* *count* times, or *NULL* on - failure. The operation is done *in-place* when *o* supports it. This is the - equivalent of the Python expression ``o *= count``. - - -.. cfunction:: PyObject* PySequence_GetItem(PyObject *o, Py_ssize_t i) - - Return the *i*th element of *o*, or *NULL* on failure. This is the equivalent of - the Python expression ``o[i]``. - - -.. cfunction:: PyObject* PySequence_GetSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2) - - Return the slice of sequence object *o* between *i1* and *i2*, or *NULL* on - failure. This is the equivalent of the Python expression ``o[i1:i2]``. - - -.. cfunction:: int PySequence_SetItem(PyObject *o, Py_ssize_t i, PyObject *v) - - Assign object *v* to the *i*th element of *o*. Returns ``-1`` on failure. This - is the equivalent of the Python statement ``o[i] = v``. This function *does - not* steal a reference to *v*. - - -.. cfunction:: int PySequence_DelItem(PyObject *o, Py_ssize_t i) - - Delete the *i*th element of object *o*. Returns ``-1`` on failure. This is the - equivalent of the Python statement ``del o[i]``. - - -.. cfunction:: int PySequence_SetSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2, PyObject *v) - - Assign the sequence object *v* to the slice in sequence object *o* from *i1* to - *i2*. This is the equivalent of the Python statement ``o[i1:i2] = v``. - - -.. cfunction:: int PySequence_DelSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2) - - Delete the slice in sequence object *o* from *i1* to *i2*. Returns ``-1`` on - failure. This is the equivalent of the Python statement ``del o[i1:i2]``. - - -.. cfunction:: Py_ssize_t PySequence_Count(PyObject *o, PyObject *value) - - Return the number of occurrences of *value* in *o*, that is, return the number - of keys for which ``o[key] == value``. On failure, return ``-1``. This is - equivalent to the Python expression ``o.count(value)``. - - -.. cfunction:: int PySequence_Contains(PyObject *o, PyObject *value) - - Determine if *o* contains *value*. If an item in *o* is equal to *value*, - return ``1``, otherwise return ``0``. On error, return ``-1``. This is - equivalent to the Python expression ``value in o``. - - -.. cfunction:: Py_ssize_t PySequence_Index(PyObject *o, PyObject *value) - - Return the first index *i* for which ``o[i] == value``. On error, return - ``-1``. This is equivalent to the Python expression ``o.index(value)``. - - -.. cfunction:: PyObject* PySequence_List(PyObject *o) - - Return a list object with the same contents as the arbitrary sequence *o*. The - returned list is guaranteed to be new. - - -.. cfunction:: PyObject* PySequence_Tuple(PyObject *o) - - .. index:: builtin: tuple - - Return a tuple object with the same contents as the arbitrary sequence *o* or - *NULL* on failure. If *o* is a tuple, a new reference will be returned, - otherwise a tuple will be constructed with the appropriate contents. This is - equivalent to the Python expression ``tuple(o)``. - - -.. cfunction:: PyObject* PySequence_Fast(PyObject *o, const char *m) - - Returns the sequence *o* as a tuple, unless it is already a tuple or list, in - which case *o* is returned. Use :cfunc:`PySequence_Fast_GET_ITEM` to access the - members of the result. Returns *NULL* on failure. If the object is not a - sequence, raises :exc:`TypeError` with *m* as the message text. - - -.. cfunction:: PyObject* PySequence_Fast_GET_ITEM(PyObject *o, Py_ssize_t i) - - Return the *i*th element of *o*, assuming that *o* was returned by - :cfunc:`PySequence_Fast`, *o* is not *NULL*, and that *i* is within bounds. - - -.. cfunction:: PyObject** PySequence_Fast_ITEMS(PyObject *o) - - Return the underlying array of PyObject pointers. Assumes that *o* was returned - by :cfunc:`PySequence_Fast` and *o* is not *NULL*. - - -.. cfunction:: PyObject* PySequence_ITEM(PyObject *o, Py_ssize_t i) - - Return the *i*th element of *o* or *NULL* on failure. Macro form of - :cfunc:`PySequence_GetItem` but without checking that - :cfunc:`PySequence_Check(o)` is true and without adjustment for negative - indices. - - -.. cfunction:: Py_ssize_t PySequence_Fast_GET_SIZE(PyObject *o) - - Returns the length of *o*, assuming that *o* was returned by - :cfunc:`PySequence_Fast` and that *o* is not *NULL*. The size can also be - gotten by calling :cfunc:`PySequence_Size` on *o*, but - :cfunc:`PySequence_Fast_GET_SIZE` is faster because it can assume *o* is a list - or tuple. - - -.. _mapping: - -Mapping Protocol -================ - - -.. cfunction:: int PyMapping_Check(PyObject *o) - - Return ``1`` if the object provides mapping protocol, and ``0`` otherwise. This - function always succeeds. - - -.. cfunction:: Py_ssize_t PyMapping_Length(PyObject *o) - - .. index:: builtin: len - - Returns the number of keys in object *o* on success, and ``-1`` on failure. For - objects that do not provide mapping protocol, this is equivalent to the Python - expression ``len(o)``. - - -.. cfunction:: int PyMapping_DelItemString(PyObject *o, char *key) - - Remove the mapping for object *key* from the object *o*. Return ``-1`` on - failure. This is equivalent to the Python statement ``del o[key]``. - - -.. cfunction:: int PyMapping_DelItem(PyObject *o, PyObject *key) - - Remove the mapping for object *key* from the object *o*. Return ``-1`` on - failure. This is equivalent to the Python statement ``del o[key]``. - - -.. cfunction:: int PyMapping_HasKeyString(PyObject *o, char *key) - - On success, return ``1`` if the mapping object has the key *key* and ``0`` - otherwise. This is equivalent to the Python expression ``key in o``. - This function always succeeds. - - -.. cfunction:: int PyMapping_HasKey(PyObject *o, PyObject *key) - - Return ``1`` if the mapping object has the key *key* and ``0`` otherwise. This - is equivalent to the Python expression ``key in o``. This function always - succeeds. - - -.. cfunction:: PyObject* PyMapping_Keys(PyObject *o) - - On success, return a list of the keys in object *o*. On failure, return *NULL*. - This is equivalent to the Python expression ``o.keys()``. - - -.. cfunction:: PyObject* PyMapping_Values(PyObject *o) - - On success, return a list of the values in object *o*. On failure, return - *NULL*. This is equivalent to the Python expression ``o.values()``. - - -.. cfunction:: PyObject* PyMapping_Items(PyObject *o) - - On success, return a list of the items in object *o*, where each item is a tuple - containing a key-value pair. On failure, return *NULL*. This is equivalent to - the Python expression ``o.items()``. - - -.. cfunction:: PyObject* PyMapping_GetItemString(PyObject *o, char *key) - - Return element of *o* corresponding to the object *key* or *NULL* on failure. - This is the equivalent of the Python expression ``o[key]``. - - -.. cfunction:: int PyMapping_SetItemString(PyObject *o, char *key, PyObject *v) - - Map the object *key* to the value *v* in object *o*. Returns ``-1`` on failure. - This is the equivalent of the Python statement ``o[key] = v``. - - -.. _iterator: - -Iterator Protocol -================= - -There are only a couple of functions specifically for working with iterators. - -.. cfunction:: int PyIter_Check(PyObject *o) - - Return true if the object *o* supports the iterator protocol. - - -.. cfunction:: PyObject* PyIter_Next(PyObject *o) - - Return the next value from the iteration *o*. If the object is an iterator, - this retrieves the next value from the iteration, and returns *NULL* with no - exception set if there are no remaining items. If the object is not an - iterator, :exc:`TypeError` is raised, or if there is an error in retrieving the - item, returns *NULL* and passes along the exception. - -To write a loop which iterates over an iterator, the C code should look -something like this:: - - PyObject *iterator = PyObject_GetIter(obj); - PyObject *item; - - if (iterator == NULL) { - /* propagate error */ - } - - while (item = PyIter_Next(iterator)) { - /* do something with item */ - ... - /* release reference when done */ - Py_DECREF(item); - } - - Py_DECREF(iterator); - - if (PyErr_Occurred()) { - /* propagate error */ - } - else { - /* continue doing useful work */ - } - - -.. _abstract-buffer: - -Buffer Protocol -=============== - - -.. cfunction:: int PyObject_AsCharBuffer(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len) - - Returns a pointer to a read-only memory location useable as character- based - input. The *obj* argument must support the single-segment character buffer - interface. On success, returns ``0``, sets *buffer* to the memory location and - *buffer_len* to the buffer length. Returns ``-1`` and sets a :exc:`TypeError` - on error. - - -.. cfunction:: int PyObject_AsReadBuffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len) - - Returns a pointer to a read-only memory location containing arbitrary data. The - *obj* argument must support the single-segment readable buffer interface. On - success, returns ``0``, sets *buffer* to the memory location and *buffer_len* to - the buffer length. Returns ``-1`` and sets a :exc:`TypeError` on error. - - -.. cfunction:: int PyObject_CheckReadBuffer(PyObject *o) - - Returns ``1`` if *o* supports the single-segment readable buffer interface. - Otherwise returns ``0``. - - -.. cfunction:: int PyObject_AsWriteBuffer(PyObject *obj, void **buffer, Py_ssize_t *buffer_len) - - Returns a pointer to a writable memory location. The *obj* argument must - support the single-segment, character buffer interface. On success, returns - ``0``, sets *buffer* to the memory location and *buffer_len* to the buffer - length. Returns ``-1`` and sets a :exc:`TypeError` on error. - + object.rst + number.rst + sequence.rst + mapping.rst + iter.rst + objbuffer.rst |