diff options
Diffstat (limited to 'Doc/extending')
| -rw-r--r-- | Doc/extending/extending.rst | 20 | ||||
| -rw-r--r-- | Doc/extending/newtypes_tutorial.rst | 60 |
2 files changed, 40 insertions, 40 deletions
diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst index 068f6fc..c13b937 100644 --- a/Doc/extending/extending.rst +++ b/Doc/extending/extending.rst @@ -230,7 +230,7 @@ with an exception object:: return m; } -Note that the Python name for the exception object is :exc:`spam.error`. The +Note that the Python name for the exception object is :exc:`!spam.error`. The :c:func:`PyErr_NewException` function may create a class with the base class being :exc:`Exception` (unless another class is passed in instead of ``NULL``), described in :ref:`bltin-exceptions`. @@ -245,7 +245,7 @@ raises the exception could cause a core dump or other unintended side effects. We discuss the use of ``PyMODINIT_FUNC`` as a function return type later in this sample. -The :exc:`spam.error` exception can be raised in your extension module using a +The :exc:`!spam.error` exception can be raised in your extension module using a call to :c:func:`PyErr_SetString` as shown below:: static PyObject * @@ -315,7 +315,7 @@ contexts, as we have seen. The Module's Method Table and Initialization Function ===================================================== -I promised to show how :c:func:`spam_system` is called from Python programs. +I promised to show how :c:func:`!spam_system` is called from Python programs. First, we need to list its name and address in a "method table":: static PyMethodDef SpamMethods[] = { @@ -1030,13 +1030,13 @@ Let's follow the control flow into :c:func:`PyList_SetItem`. The list owns references to all its items, so when item 1 is replaced, it has to dispose of the original item 1. Now let's suppose the original item 1 was an instance of a user-defined class, and let's further suppose that the class defined a -:meth:`__del__` method. If this class instance has a reference count of 1, -disposing of it will call its :meth:`__del__` method. +:meth:`!__del__` method. If this class instance has a reference count of 1, +disposing of it will call its :meth:`!__del__` method. -Since it is written in Python, the :meth:`__del__` method can execute arbitrary +Since it is written in Python, the :meth:`!__del__` method can execute arbitrary Python code. Could it perhaps do something to invalidate the reference to -``item`` in :c:func:`bug`? You bet! Assuming that the list passed into -:c:func:`bug` is accessible to the :meth:`__del__` method, it could execute a +``item`` in :c:func:`!bug`? You bet! Assuming that the list passed into +:c:func:`!bug` is accessible to the :meth:`!__del__` method, it could execute a statement to the effect of ``del list[0]``, and assuming this was the last reference to that object, it would free the memory associated with it, thereby invalidating ``item``. @@ -1057,7 +1057,7 @@ increment the reference count. The correct version of the function reads:: This is a true story. An older version of Python contained variants of this bug and someone spent a considerable amount of time in a C debugger to figure out -why his :meth:`__del__` methods would fail... +why his :meth:`!__del__` methods would fail... The second case of problems with a borrowed reference is a variant involving threads. Normally, multiple threads in the Python interpreter can't get in each @@ -1224,7 +1224,7 @@ The function :c:func:`PySpam_System` is a plain C function, declared return system(command); } -The function :c:func:`spam_system` is modified in a trivial way:: +The function :c:func:`!spam_system` is modified in a trivial way:: static PyObject * spam_system(PyObject *self, PyObject *args) diff --git a/Doc/extending/newtypes_tutorial.rst b/Doc/extending/newtypes_tutorial.rst index 80c8ea7..7180191 100644 --- a/Doc/extending/newtypes_tutorial.rst +++ b/Doc/extending/newtypes_tutorial.rst @@ -36,7 +36,7 @@ So, if you want to define a new extension type, you need to create a new type object. This sort of thing can only be explained by example, so here's a minimal, but -complete, module that defines a new type named :class:`Custom` inside a C +complete, module that defines a new type named :class:`!Custom` inside a C extension module :mod:`!custom`: .. note:: @@ -50,9 +50,9 @@ extension module :mod:`!custom`: Now that's quite a bit to take in at once, but hopefully bits will seem familiar from the previous chapter. This file defines three things: -#. What a :class:`Custom` **object** contains: this is the ``CustomObject`` - struct, which is allocated once for each :class:`Custom` instance. -#. How the :class:`Custom` **type** behaves: this is the ``CustomType`` struct, +#. What a :class:`!Custom` **object** contains: this is the ``CustomObject`` + struct, which is allocated once for each :class:`!Custom` instance. +#. How the :class:`!Custom` **type** behaves: this is the ``CustomType`` struct, which defines a set of flags and function pointers that the interpreter inspects when specific operations are requested. #. How to initialize the :mod:`!custom` module: this is the ``PyInit_custom`` @@ -128,7 +128,7 @@ our objects and in some error messages, for example: Note that the name is a dotted name that includes both the module name and the name of the type within the module. The module in this case is :mod:`!custom` and -the type is :class:`Custom`, so we set the type name to :class:`custom.Custom`. +the type is :class:`!Custom`, so we set the type name to :class:`!custom.Custom`. Using the real dotted import path is important to make your type compatible with the :mod:`pydoc` and :mod:`pickle` modules. :: @@ -136,7 +136,7 @@ with the :mod:`pydoc` and :mod:`pickle` modules. :: .tp_itemsize = 0, This is so that Python knows how much memory to allocate when creating -new :class:`Custom` instances. :c:member:`~PyTypeObject.tp_itemsize` is +new :class:`!Custom` instances. :c:member:`~PyTypeObject.tp_itemsize` is only used for variable-sized objects and should otherwise be zero. .. note:: @@ -188,7 +188,7 @@ set to ``NULL``. :: } This adds the type to the module dictionary. This allows us to create -:class:`Custom` instances by calling the :class:`Custom` class: +:class:`!Custom` instances by calling the :class:`!Custom` class: .. code-block:: pycon @@ -239,7 +239,7 @@ adds these capabilities: This version of the module has a number of changes. -The :class:`Custom` type now has three data attributes in its C struct, +The :class:`!Custom` type now has three data attributes in its C struct, *first*, *last*, and *number*. The *first* and *last* variables are Python strings containing first and last names. The *number* attribute is a C integer. @@ -314,7 +314,7 @@ The ``tp_new`` handler is responsible for creating (as opposed to initializing) objects of the type. It is exposed in Python as the :meth:`__new__` method. It is not required to define a ``tp_new`` member, and indeed many extension types will simply reuse :c:func:`PyType_GenericNew` as done in the first -version of the ``Custom`` type above. In this case, we use the ``tp_new`` +version of the :class:`!Custom` type above. In this case, we use the ``tp_new`` handler to initialize the ``first`` and ``last`` attributes to non-``NULL`` default values. @@ -453,7 +453,7 @@ Further, the attributes can be deleted, setting the C pointers to ``NULL``. Eve though we can make sure the members are initialized to non-``NULL`` values, the members can be set to ``NULL`` if the attributes are deleted. -We define a single method, :meth:`Custom.name()`, that outputs the objects name as the +We define a single method, :meth:`!Custom.name()`, that outputs the objects name as the concatenation of the first and last names. :: static PyObject * @@ -470,8 +470,8 @@ concatenation of the first and last names. :: return PyUnicode_FromFormat("%S %S", self->first, self->last); } -The method is implemented as a C function that takes a :class:`Custom` (or -:class:`Custom` subclass) instance as the first argument. Methods always take an +The method is implemented as a C function that takes a :class:`!Custom` (or +:class:`!Custom` subclass) instance as the first argument. Methods always take an instance as the first argument. Methods often take positional and keyword arguments as well, but in this case we don't take any and don't need to accept a positional argument tuple or keyword argument dictionary. This method is @@ -482,8 +482,8 @@ equivalent to the Python method: def name(self): return "%s %s" % (self.first, self.last) -Note that we have to check for the possibility that our :attr:`first` and -:attr:`last` members are ``NULL``. This is because they can be deleted, in which +Note that we have to check for the possibility that our :attr:`!first` and +:attr:`!last` members are ``NULL``. This is because they can be deleted, in which case they are set to ``NULL``. It would be better to prevent deletion of these attributes and to restrict the attribute values to be strings. We'll see how to do that in the next section. @@ -512,7 +512,7 @@ to add the :c:macro:`Py_TPFLAGS_BASETYPE` to our class flag definition:: .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, -We rename :c:func:`PyInit_custom` to :c:func:`PyInit_custom2`, update the +We rename :c:func:`!PyInit_custom` to :c:func:`!PyInit_custom2`, update the module name in the :c:type:`PyModuleDef` struct, and update the full class name in the :c:type:`PyTypeObject` struct. @@ -531,18 +531,18 @@ Finally, we update our :file:`setup.py` file to build the new module: Providing finer control over data attributes ============================================ -In this section, we'll provide finer control over how the :attr:`first` and -:attr:`last` attributes are set in the :class:`Custom` example. In the previous -version of our module, the instance variables :attr:`first` and :attr:`last` +In this section, we'll provide finer control over how the :attr:`!first` and +:attr:`!last` attributes are set in the :class:`!Custom` example. In the previous +version of our module, the instance variables :attr:`!first` and :attr:`!last` could be set to non-string values or even deleted. We want to make sure that these attributes always contain strings. .. literalinclude:: ../includes/custom3.c -To provide greater control, over the :attr:`first` and :attr:`last` attributes, +To provide greater control, over the :attr:`!first` and :attr:`!last` attributes, we'll use custom getter and setter functions. Here are the functions for -getting and setting the :attr:`first` attribute:: +getting and setting the :attr:`!first` attribute:: static PyObject * Custom_getfirst(CustomObject *self, void *closure) @@ -571,13 +571,13 @@ getting and setting the :attr:`first` attribute:: return 0; } -The getter function is passed a :class:`Custom` object and a "closure", which is +The getter function is passed a :class:`!Custom` object and a "closure", which is a void pointer. In this case, the closure is ignored. (The closure supports an advanced usage in which definition data is passed to the getter and setter. This could, for example, be used to allow a single set of getter and setter functions that decide the attribute to get or set based on data in the closure.) -The setter function is passed the :class:`Custom` object, the new value, and the +The setter function is passed the :class:`!Custom` object, the new value, and the closure. The new value may be ``NULL``, in which case the attribute is being deleted. In our setter, we raise an error if the attribute is deleted or if its new value is not a string. @@ -666,11 +666,11 @@ still has a reference from itself. Its reference count doesn't drop to zero. Fortunately, Python's cyclic garbage collector will eventually figure out that the list is garbage and free it. -In the second version of the :class:`Custom` example, we allowed any kind of -object to be stored in the :attr:`first` or :attr:`last` attributes [#]_. +In the second version of the :class:`!Custom` example, we allowed any kind of +object to be stored in the :attr:`!first` or :attr:`!last` attributes [#]_. Besides, in the second and third versions, we allowed subclassing -:class:`Custom`, and subclasses may add arbitrary attributes. For any of -those two reasons, :class:`Custom` objects can participate in cycles: +:class:`!Custom`, and subclasses may add arbitrary attributes. For any of +those two reasons, :class:`!Custom` objects can participate in cycles: .. code-block:: pycon @@ -680,8 +680,8 @@ those two reasons, :class:`Custom` objects can participate in cycles: >>> n = Derived() >>> n.some_attribute = n -To allow a :class:`Custom` instance participating in a reference cycle to -be properly detected and collected by the cyclic GC, our :class:`Custom` type +To allow a :class:`!Custom` instance participating in a reference cycle to +be properly detected and collected by the cyclic GC, our :class:`!Custom` type needs to fill two additional slots and to enable a flag that enables these slots: .. literalinclude:: ../includes/custom4.c @@ -811,7 +811,7 @@ increases an internal counter: .. literalinclude:: ../includes/sublist.c -As you can see, the source code closely resembles the :class:`Custom` examples in +As you can see, the source code closely resembles the :class:`!Custom` examples in previous sections. We will break down the main differences between them. :: typedef struct { @@ -879,7 +879,7 @@ slot with :c:func:`PyType_GenericNew` -- the allocation function from the base type will be inherited. After that, calling :c:func:`PyType_Ready` and adding the type object to the -module is the same as with the basic :class:`Custom` examples. +module is the same as with the basic :class:`!Custom` examples. .. rubric:: Footnotes |