FM / c-api

/usr/share/doc/python2-docs/html/_sources/c-api/

/usr/share/doc/python2-docs/html/_sources/c-api

Name	Size	Mode	Actions
abstract.rst.txt	702	0644	edit dl rm
allocation.rst.txt	4796	0644	edit dl rm
arg.rst.txt	26004	0644	edit dl rm
bool.rst.txt	1304	0644	edit dl rm
buffer.rst.txt	22965	0644	edit dl rm
bytearray.rst.txt	2181	0644	edit dl rm
capsule.rst.txt	5741	0644	edit dl rm
cell.rst.txt	1940	0644	edit dl rm
class.rst.txt	1866	0644	edit dl rm
cobject.rst.txt	1870	0644	edit dl rm
code.rst.txt	1635	0644	edit dl rm
codec.rst.txt	4643	0644	edit dl rm
complex.rst.txt	4079	0644	edit dl rm
concrete.rst.txt	1963	0644	edit dl rm
conversion.rst.txt	7092	0644	edit dl rm
datetime.rst.txt	6413	0644	edit dl rm
descriptor.rst.txt	1296	0644	edit dl rm
dict.rst.txt	7757	0644	edit dl rm
exceptions.rst.txt	35304	0644	edit dl rm
file.rst.txt	6198	0644	edit dl rm
float.rst.txt	3371	0644	edit dl rm
function.rst.txt	2421	0644	edit dl rm
gcsupport.rst.txt	6587	0644	edit dl rm
gen.rst.txt	920	0644	edit dl rm
import.rst.txt	11221	0644	edit dl rm
index.rst.txt	578	0644	edit dl rm
init.rst.txt	49160	0644	edit dl rm
int.rst.txt	4578	0644	edit dl rm
intro.rst.txt	28473	0644	edit dl rm
iter.rst.txt	1390	0644	edit dl rm
iterator.rst.txt	1796	0644	edit dl rm
list.rst.txt	6362	0644	edit dl rm
long.rst.txt	7987	0644	edit dl rm
mapping.rst.txt	2874	0644	edit dl rm
marshal.rst.txt	3985	0644	edit dl rm
memory.rst.txt	11556	0644	edit dl rm
method.rst.txt	2099	0644	edit dl rm
module.rst.txt	3867	0644	edit dl rm
none.rst.txt	697	0644	edit dl rm
number.rst.txt	11939	0644	edit dl rm
objbuffer.rst.txt	2516	0644	edit dl rm
object.rst.txt	17491	0644	edit dl rm
objimpl.rst.txt	305	0644	edit dl rm
refcounting.rst.txt	2934	0644	edit dl rm
reflection.rst.txt	1567	0644	edit dl rm
sequence.rst.txt	8716	0644	edit dl rm
set.rst.txt	6588	0644	edit dl rm
slice.rst.txt	2979	0644	edit dl rm
string.rst.txt	15422	0644	edit dl rm
structures.rst.txt	14966	0644	edit dl rm
sys.rst.txt	5714	0644	edit dl rm
tuple.rst.txt	5491	0644	edit dl rm
type.rst.txt	2761	0644	edit dl rm
typeobj.rst.txt	66936	0644	edit dl rm
unicode.rst.txt	45126	0644	edit dl rm
utilities.rst.txt	415	0644	edit dl rm
veryhigh.rst.txt	13363	0644	edit dl rm
weakref.rst.txt	2820	0644	edit dl rm

Edit: /usr/share/doc/python2-docs/html/_sources/c-api/capsule.rst.txt (5741B)

.. highlightlang:: c

.. _capsules:

Capsules
--------

.. index:: object: Capsule

Refer to :ref:`using-capsules` for more information on using these objects.

.. versionadded:: 2.7

.. c:type:: PyCapsule

This subtype of :c:type:`PyObject` represents an opaque value, useful for C
   extension modules who need to pass an opaque value (as a :c:type:`void\*`
   pointer) through Python code to other C code.  It is often used to make a C
   function pointer defined in one module available to other modules, so the
   regular import mechanism can be used to access C APIs defined in dynamically
   loaded modules.

.. c:type:: PyCapsule_Destructor

The type of a destructor callback for a capsule.  Defined as::

typedef void (*PyCapsule_Destructor)(PyObject *);

See :c:func:`PyCapsule_New` for the semantics of PyCapsule_Destructor
   callbacks.

.. c:function:: int PyCapsule_CheckExact(PyObject *p)

Return true if its argument is a :c:type:`PyCapsule`.

.. c:function:: PyObject* PyCapsule_New(void *pointer, const char *name, PyCapsule_Destructor destructor)

Create a :c:type:`PyCapsule` encapsulating the *pointer*.  The *pointer*
   argument may not be *NULL*.

On failure, set an exception and return *NULL*.

The *name* string may either be *NULL* or a pointer to a valid C string.  If
   non-*NULL*, this string must outlive the capsule.  (Though it is permitted to
   free it inside the *destructor*.)

If the *destructor* argument is not *NULL*, it will be called with the
   capsule as its argument when it is destroyed.

If this capsule will be stored as an attribute of a module, the *name* should
   be specified as ``modulename.attributename``.  This will enable other modules
   to import the capsule using :c:func:`PyCapsule_Import`.

.. c:function:: void* PyCapsule_GetPointer(PyObject *capsule, const char *name)

Retrieve the *pointer* stored in the capsule.  On failure, set an exception
   and return *NULL*.

The *name* parameter must compare exactly to the name stored in the capsule.
   If the name stored in the capsule is *NULL*, the *name* passed in must also
   be *NULL*.  Python uses the C function :c:func:`strcmp` to compare capsule
   names.

.. c:function:: PyCapsule_Destructor PyCapsule_GetDestructor(PyObject *capsule)

Return the current destructor stored in the capsule.  On failure, set an
   exception and return *NULL*.

It is legal for a capsule to have a *NULL* destructor.  This makes a *NULL*
   return code somewhat ambiguous; use :c:func:`PyCapsule_IsValid` or
   :c:func:`PyErr_Occurred` to disambiguate.

.. c:function:: void* PyCapsule_GetContext(PyObject *capsule)

Return the current context stored in the capsule.  On failure, set an
   exception and return *NULL*.

It is legal for a capsule to have a *NULL* context.  This makes a *NULL*
   return code somewhat ambiguous; use :c:func:`PyCapsule_IsValid` or
   :c:func:`PyErr_Occurred` to disambiguate.

.. c:function:: const char* PyCapsule_GetName(PyObject *capsule)

Return the current name stored in the capsule.  On failure, set an exception
   and return *NULL*.

It is legal for a capsule to have a *NULL* name.  This makes a *NULL* return
   code somewhat ambiguous; use :c:func:`PyCapsule_IsValid` or
   :c:func:`PyErr_Occurred` to disambiguate.

.. c:function:: void* PyCapsule_Import(const char *name, int no_block)

Import a pointer to a C object from a capsule attribute in a module.  The
   *name* parameter should specify the full name to the attribute, as in
   ``module.attribute``.  The *name* stored in the capsule must match this
   string exactly.  If *no_block* is true, import the module without blocking
   (using :c:func:`PyImport_ImportModuleNoBlock`).  If *no_block* is false,
   import the module conventionally (using :c:func:`PyImport_ImportModule`).

Return the capsule's internal *pointer* on success.  On failure, set an
   exception and return *NULL*.

.. c:function:: int PyCapsule_IsValid(PyObject *capsule, const char *name)

Determines whether or not *capsule* is a valid capsule.  A valid capsule is
   non-*NULL*, passes :c:func:`PyCapsule_CheckExact`, has a non-*NULL* pointer
   stored in it, and its internal name matches the *name* parameter.  (See
   :c:func:`PyCapsule_GetPointer` for information on how capsule names are
   compared.)

In other words, if :c:func:`PyCapsule_IsValid` returns a true value, calls to
   any of the accessors (any function starting with :c:func:`PyCapsule_Get`) are
   guaranteed to succeed.

Return a nonzero value if the object is valid and matches the name passed in.
   Return ``0`` otherwise.  This function will not fail.

.. c:function:: int PyCapsule_SetContext(PyObject *capsule, void *context)

Set the context pointer inside *capsule* to *context*.

Return ``0`` on success.  Return nonzero and set an exception on failure.

.. c:function:: int PyCapsule_SetDestructor(PyObject *capsule, PyCapsule_Destructor destructor)

Set the destructor inside *capsule* to *destructor*.

Return ``0`` on success.  Return nonzero and set an exception on failure.

.. c:function:: int PyCapsule_SetName(PyObject *capsule, const char *name)

Set the name inside *capsule* to *name*.  If non-*NULL*, the name must
   outlive the capsule.  If the previous *name* stored in the capsule was not
   *NULL*, no attempt is made to free it.

Return ``0`` on success.  Return nonzero and set an exception on failure.

.. c:function:: int PyCapsule_SetPointer(PyObject *capsule, void *pointer)

Set the void pointer inside *capsule* to *pointer*.  The pointer may not be
   *NULL*.

Return ``0`` on success.  Return nonzero and set an exception on failure.

cmd: