GNU Info

(python2.1-api.info)Defining New Object Types

---

Next: Reporting Bugs Prev: Memory Management Up: Top

---

Enter node , (file) or (file)node

Defining New Object Types
*************************

`PyObject* _PyObject_New(PyTypeObject *type)'

`PyVarObject* _PyObject_NewVar(PyTypeObject *type, int size)'

`void _PyObject_Del(PyObject *op)'

`PyObject* PyObject_Init(PyObject *op, PyTypeObject *type)'
     Initialize a newly-allocated object OP with its type and initial
     reference.  Returns the initialized object.  If TYPE indicates
     that the object participates in the cyclic garbage detector, it it
     added to the detector's set of observed objects.  Other fields of
     the object are not affected.

`PyVarObject* PyObject_InitVar(PyVarObject *op, PyTypeObject *type, int size)'
     This does everything `PyObject_Init()' does, and also initializes
     the length information for a variable-size object.

`TYPE* PyObject_New(TYPE, PyTypeObject *type)'
     Allocate a new Python object using the C structure type TYPE and
     the Python type object TYPE.  Fields not defined by the Python
     object header are not initialized; the object's reference count
     will be one.  The size of the memory allocation is determined from
     the `tp_basicsize' field of the type object.

`TYPE* PyObject_NewVar(TYPE, PyTypeObject *type, int size)'
     Allocate a new Python object using the C structure type TYPE and
     the Python type object TYPE.  Fields not defined by the Python
     object header are not initialized.  The allocated memory allows
     for the TYPE structure plus SIZE fields of the size given by the
     `tp_itemsize' field of TYPE.  This is useful for implementing
     objects like tuples, which are able to determine their size at
     construction time.  Embedding the array of fields into the same
     allocation decreases the number of allocations, improving the
     memory management efficiency.

`void PyObject_Del(PyObject *op)'
     Releases memory allocated to an object using `PyObject_New()' or
     `PyObject_NewVar()'.  This is normally called from the
     `tp_dealloc' handler specified in the object's type.  The fields
     of the object should not be accessed after this call as the memory
     is no longer a valid Python object.

`TYPE* PyObject_NEW(TYPE, PyTypeObject *type)'
     Macro version of `PyObject_New()', to gain performance at the
     expense of safety.  This does not check TYPE for a `NULL' value.

`TYPE* PyObject_NEW_VAR(TYPE, PyTypeObject *type, int size)'
     Macro version of `PyObject_NewVar()', to gain performance at the
     expense of safety.  This does not check TYPE for a `NULL' value.

`void PyObject_DEL(PyObject *op)'
     Macro version of `PyObject_Del()'.

`PyObject* Py_InitModule(char *name, PyMethodDef *methods)'
     Create a new module object based on a name and table of functions,
     returning the new module object.

`PyObject* Py_InitModule3(char *name, PyMethodDef *methods, char *doc)'
     Create a new module object based on a name and table of functions,
     returning the new module object.  If DOC is non-`NULL', it will be
     used to define the docstring for the module.

`PyObject* Py_InitModule4(char *name, PyMethodDef *methods, char *doc, PyObject *self, int apiver)'
     Create a new module object based on a name and table of functions,
     returning the new module object.  If DOC is non-`NULL', it will be
     used to define the docstring for the module.  If SELF is
     non-`NULL', it will passed to the functions of the module as their
     (otherwise `NULL') first parameter.  (This was added as an
     experimental feature, and there are no known uses in the current
     version of Python.)  For APIVER, the only value which should be
     passed is defined by the constant `PYTHON_API_VERSION'.

     *Note:*  Most uses of this function should probably be using the
     `Py_InitModule3()' instead; only use this if you are sure you need
     it.

`int PyArg_ParseTuple(PyObject *args, char *format, ...)'
     Parse the parameters of a function that takes only positional
     parameters into local variables.  See  for more information.

`int PyArg_ParseTupleAndKeywords(PyObject *args, PyObject *kw, char *format, char *keywords[], ...)'
     Parse the parameters of a function that takes both positional and
     keyword parameters into local variables.  See  for more
     information.

`int PyArg_Parse(PyObject *args, char *format, ...)'
     Function used to deconstruct the argument lists of "old-style"
     functions -- these are functions which use the `METH_OLDARGS'
     parameter parsing method.  This is not recommended for new code,
     and most code in the standard interpreter has been modified to no
     longer use this.

Py_BuildValue

DL_IMPORT

`PyObject _Py_NoneStruct'
     Object which is visible in Python as `None'.  This should only be
     accessed using the `Py_None' macro, which evaluates to a pointer
     to this object.

Common Object Structures

Mapping Object Structures

Number Object Structures

Sequence Object Structures

Buffer Object Structures

Supporting Cyclic Garbarge Collection