Allocating Objects on the Heap¶
- PyObject*_PyObject_New(PyTypeObject*type)¶
- Return value: New reference.
- PyVarObject*_PyObject_NewVar(PyTypeObject*type,Py_ssize_tsize)¶
- Return value: New reference.
- PyObject*PyObject_Init(PyObject*op,PyTypeObject*type)¶
- Return value: Borrowed reference. Part of theStable ABI.
Initialize a newly allocated objectop with its type and initialreference. Returns the initialized object. Other fields of the object arenot affected.
- PyVarObject*PyObject_InitVar(PyVarObject*op,PyTypeObject*type,Py_ssize_tsize)¶
- Return value: Borrowed reference. Part of theStable ABI.
This does everything
PyObject_Init()
does, and also initializes thelength information for a variable-size object.
- PyObject_New(TYPE,typeobj)¶
Allocate a new Python object using the C structure typeTYPEand the Python type objecttypeobj (
PyTypeObject*
).Fields not defined by the Python object header are not initialized.The caller will own the only reference to the object(i.e. its reference count will be one).The size of the memory allocation is determined from thetp_basicsize
field of the type object.Note that this function is unsuitable iftypeobj has
Py_TPFLAGS_HAVE_GC
set. For such objects,usePyObject_GC_New()
instead.
- PyObject_NewVar(TYPE,typeobj,size)¶
Allocate a new Python object using the C structure typeTYPE and thePython type objecttypeobj (
PyTypeObject*
).Fields not defined by the Python object headerare not initialized. The allocated memory allows for theTYPE structureplussize (Py_ssize_t
) fields of the sizegiven by thetp_itemsize
field oftypeobj. This is useful for implementing objects like tuples, which areable to determine their size at construction time. Embedding the array offields into the same allocation decreases the number of allocations,improving the memory management efficiency.Note that this function is unsuitable iftypeobj has
Py_TPFLAGS_HAVE_GC
set. For such objects,usePyObject_GC_NewVar()
instead.
- voidPyObject_Del(void*op)¶
Releases memory allocated to an object using
PyObject_New
orPyObject_NewVar
. This is normally called from thetp_dealloc
handler specified in the object’s type. The fields ofthe object should not be accessed after this call as the memory is nolonger a valid Python object.
- PyObject_Py_NoneStruct¶
Object which is visible in Python as
None
. This should only be accessedusing thePy_None
macro, which evaluates to a pointer to thisobject.
See also
PyModule_Create()
To allocate and create extension modules.