view Doc/c-api/function.rst @ 87690:66c1c9f32567 default tip

Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859
author Radomir Dopieralski <devel@sheep.art.pl>
date Tue, 03 Dec 2013 16:02:48 +0100
parents e1dbc72bd97f
children
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.. highlightlang:: c

.. _function-objects:

Function Objects
----------------

.. index:: object: function

There are a few functions specific to Python functions.


.. c:type:: PyFunctionObject

   The C structure used for functions.


.. c:var:: PyTypeObject PyFunction_Type

   .. index:: single: MethodType (in module types)

   This is an instance of :c:type:`PyTypeObject` and represents the Python function
   type.  It is exposed to Python programmers as ``types.FunctionType``.


.. c:function:: int PyFunction_Check(PyObject *o)

   Return true if *o* is a function object (has type :c:data:`PyFunction_Type`).
   The parameter must not be *NULL*.


.. c:function:: PyObject* PyFunction_New(PyObject *code, PyObject *globals)

   Return a new function object associated with the code object *code*. *globals*
   must be a dictionary with the global variables accessible to the function.

   The function's docstring, name and *__module__* are retrieved from the code
   object, the argument defaults and closure are set to *NULL*.


.. c:function:: PyObject* PyFunction_NewWithQualName(PyObject *code, PyObject *globals, PyObject *qualname)

   As :c:func:`PyFunction_New`, but also allows to set the function object's
   ``__qualname__`` attribute.  *qualname* should be a unicode object or NULL;
   if NULL, the ``__qualname__`` attribute is set to the same value as its
   ``__name__`` attribute.

   .. versionadded:: 3.3


.. c:function:: PyObject* PyFunction_GetCode(PyObject *op)

   Return the code object associated with the function object *op*.


.. c:function:: PyObject* PyFunction_GetGlobals(PyObject *op)

   Return the globals dictionary associated with the function object *op*.


.. c:function:: PyObject* PyFunction_GetModule(PyObject *op)

   Return the *__module__* attribute of the function object *op*. This is normally
   a string containing the module name, but can be set to any other object by
   Python code.


.. c:function:: PyObject* PyFunction_GetDefaults(PyObject *op)

   Return the argument default values of the function object *op*. This can be a
   tuple of arguments or *NULL*.


.. c:function:: int PyFunction_SetDefaults(PyObject *op, PyObject *defaults)

   Set the argument default values for the function object *op*. *defaults* must be
   *Py_None* or a tuple.

   Raises :exc:`SystemError` and returns ``-1`` on failure.


.. c:function:: PyObject* PyFunction_GetClosure(PyObject *op)

   Return the closure associated with the function object *op*. This can be *NULL*
   or a tuple of cell objects.


.. c:function:: int PyFunction_SetClosure(PyObject *op, PyObject *closure)

   Set the closure associated with the function object *op*. *closure* must be
   *Py_None* or a tuple of cell objects.

   Raises :exc:`SystemError` and returns ``-1`` on failure.


.. c:function:: PyObject *PyFunction_GetAnnotations(PyObject *op)

   Return the annotations of the function object *op*. This can be a
   mutable dictionary or *NULL*.


.. c:function:: int PyFunction_SetAnnotations(PyObject *op, PyObject *annotations)

   Set the annotations for the function object *op*. *annotations*
   must be a dictionary or *Py_None*.

   Raises :exc:`SystemError` and returns ``-1`` on failure.