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10. Defining New Object Types

PyObject* `_PyObject_New`(PyTypeObject *type)
  Return value: New reference.

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

void `_PyObject_Del`(PyObject *op)

PyObject* `PyObject_Init`(PyObject *op, PyTypeObject *type)
  Return value: Borrowed reference.
  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)
  Return value: Borrowed reference.
  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)
  Return value: Borrowed reference.
  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)
  Return value: Borrowed reference.
  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 Extending and Embedding the Python Interpreter 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 Extending and Embedding the Python Interpreter 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.

Subsections

- 10.1 Common Object Structures
- 10.2 Mapping Object Structures
- 10.3 Number Object Structures
- 10.4 Sequence Object Structures
- 10.5 Buffer Object Structures
- 10.6 Supporting Cyclic Garbarge Collection
  - 10.6.1 Example Cycle Collector Support