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diff --git a/Doc/glossary.rst b/Doc/glossary.rst index 36832a3..648c679 100644 --- a/Doc/glossary.rst +++ b/Doc/glossary.rst @@ -69,11 +69,34 @@ Glossary :ref:`the difference between arguments and parameters <faq-argument-vs-parameter>`, and :pep:`362`. + asynchronous context manager + An object which controls the environment seen in an + :keyword:`async with` statement by defining :meth:`__aenter__` and + :meth:`__aexit__` methods. Introduced by :pep:`492`. + + asynchronous iterable + An object, that can be used in an :keyword:`async for` statement. + Must return an :term:`awaitable` from its :meth:`__aiter__` method, + which should in turn be resolved in an :term:`asynchronous iterator` + object. Introduced by :pep:`492`. + + asynchronous iterator + An object that implements :meth:`__aiter__` and :meth:`__anext__` + methods, that must return :term:`awaitable` objects. + :keyword:`async for` resolves awaitable returned from asynchronous + iterator's :meth:`__anext__` method until it raises + :exc:`StopAsyncIteration` exception. Introduced by :pep:`492`. + attribute A value associated with an object which is referenced by name using dotted expressions. For example, if an object *o* has an attribute *a* it would be referenced as *o.a*. + awaitable + An object that can be used in an :keyword:`await` expression. Can be + a :term:`coroutine` or an object with an :meth:`__await__` method. + See also :pep:`492`. + BDFL Benevolent Dictator For Life, a.k.a. `Guido van Rossum <https://www.python.org/~guido/>`_, Python's creator. @@ -86,12 +109,21 @@ Glossary A :term:`text file` reads and writes :class:`str` objects. bytes-like object - An object that supports the :ref:`bufferobjects`, like :class:`bytes`, - :class:`bytearray` or :class:`memoryview`. Bytes-like objects can - be used for various operations that expect binary data, such as - compression, saving to a binary file or sending over a socket. - Some operations need the binary data to be mutable, in which case - not all bytes-like objects can apply. + An object that supports the :ref:`bufferobjects` and can + export a C-:term:`contiguous` buffer. This includes all :class:`bytes`, + :class:`bytearray`, and :class:`array.array` objects, as well as many + common :class:`memoryview` objects. Bytes-like objects can + be used for various operations that work with binary data; these include + compression, saving to a binary file, and sending over a socket. + + Some operations need the binary data to be mutable. The documentation + often refers to these as "read-write bytes-like objects". Example + mutable buffer objects include :class:`bytearray` and a + :class:`memoryview` of a :class:`bytearray`. + Other operations require the binary data to be stored in + immutable objects ("read-only bytes-like objects"); examples + of these include :class:`bytes` and a :class:`memoryview` + of a :class:`bytes` object. bytecode Python source code is compiled into bytecode, the internal representation @@ -139,6 +171,32 @@ Glossary statement by defining :meth:`__enter__` and :meth:`__exit__` methods. See :pep:`343`. + contiguous + .. index:: C-contiguous, Fortran contiguous + + A buffer is considered contiguous exactly if it is either + *C-contiguous* or *Fortran contiguous*. Zero-dimensional buffers are + C and Fortran contiguous. In one-dimensional arrays, the items + must be layed out in memory next to each other, in order of + increasing indexes starting from zero. In multidimensional + C-contiguous arrays, the last index varies the fastest when + visiting items in order of memory address. However, in + Fortran contiguous arrays, the first index varies the fastest. + + coroutine + Coroutines is a more generalized form of subroutines. Subroutines are + entered at one point and exited at another point. Coroutines can be + entered, exited, and resumed at many different points. They can be + implemented with the :keyword:`async def` statement. See also + :pep:`492`. + + coroutine function + A function which returns a :term:`coroutine` object. A coroutine + function may be defined with the :keyword:`async def` statement, + and may contain :keyword:`await`, :keyword:`async for`, and + :keyword:`async with` keywords. These were introduced + by :pep:`492`. + CPython The canonical implementation of the Python programming language, as distributed on `python.org <https://www.python.org>`_. The term "CPython" @@ -250,10 +308,14 @@ Glossary A synonym for :term:`file object`. finder - An object that tries to find the :term:`loader` for a module. It must - implement either a method named :meth:`find_loader` or a method named - :meth:`find_module`. See :pep:`302` and :pep:`420` for details and - :class:`importlib.abc.Finder` for an :term:`abstract base class`. + An object that tries to find the :term:`loader` for a module that is + being imported. + + Since Python 3.3, there are two types of finder: :term:`meta path finders + <meta path finder>` for use with :data:`sys.meta_path`, and :term:`path + entry finders <path entry finder>` for use with :data:`sys.path_hooks`. + + See :pep:`302`, :pep:`420` and :pep:`451` for much more detail. floor division Mathematical division that rounds down to nearest integer. The floor @@ -298,14 +360,23 @@ Glossary .. index:: single: generator generator - A function which returns an iterator. It looks like a normal function - except that it contains :keyword:`yield` statements for producing a series - of values usable in a for-loop or that can be retrieved one at a time with - the :func:`next` function. Each :keyword:`yield` temporarily suspends - processing, remembering the location execution state (including local - variables and pending try-statements). When the generator resumes, it - picks-up where it left-off (in contrast to functions which start fresh on - every invocation). + A function which returns a :term:`generator iterator`. It looks like a + normal function except that it contains :keyword:`yield` expressions + for producing a series of values usable in a for-loop or that can be + retrieved one at a time with the :func:`next` function. + + Usually refers to a generator function, but may refer to a + *generator iterator* in some contexts. In cases where the intended + meaning isn't clear, using the full terms avoids ambiguity. + + generator iterator + An object created by a :term:`generator` function. + + Each :keyword:`yield` temporarily suspends processing, remembering the + location execution state (including local variables and pending + try-statements). When the *generator iterator* resumes, it picks-up where + it left-off (in contrast to functions which start fresh on every + invocation). .. index:: single: generator expression @@ -410,6 +481,19 @@ Glossary than compiled ones, though their programs generally also run more slowly. See also :term:`interactive`. + interpreter shutdown + When asked to shut down, the Python interpreter enters a special phase + where it gradually releases all allocated resources, such as modules + and various critical internal structures. It also makes several calls + to the :term:`garbage collector <garbage collection>`. This can trigger + the execution of code in user-defined destructors or weakref callbacks. + Code executed during the shutdown phase can encounter various + exceptions as the resources it relies on may not function anymore + (common examples are library modules or the warnings machinery). + + The main reason for interpreter shutdown is that the ``__main__`` module + or the script being run has finished executing. + iterable An object capable of returning its members one at a time. Examples of iterables include all sequence types (such as :class:`list`, :class:`str`, @@ -452,12 +536,13 @@ Glossary A number of tools in Python accept key functions to control how elements are ordered or grouped. They include :func:`min`, :func:`max`, - :func:`sorted`, :meth:`list.sort`, :func:`heapq.nsmallest`, - :func:`heapq.nlargest`, and :func:`itertools.groupby`. + :func:`sorted`, :meth:`list.sort`, :func:`heapq.merge`, + :func:`heapq.nsmallest`, :func:`heapq.nlargest`, and + :func:`itertools.groupby`. There are several ways to create a key function. For example. the :meth:`str.lower` method can serve as a key function for case insensitive - sorts. Alternatively, an ad-hoc key function can be built from a + sorts. Alternatively, a key function can be built from a :keyword:`lambda` expression such as ``lambda r: (r[0], r[2])``. Also, the :mod:`operator` module provides three key function constructors: :func:`~operator.attrgetter`, :func:`~operator.itemgetter`, and @@ -512,10 +597,13 @@ Glossary :class:`collections.OrderedDict` and :class:`collections.Counter`. meta path finder - A finder returned by a search of :data:`sys.meta_path`. Meta path + A :term:`finder` returned by a search of :data:`sys.meta_path`. Meta path finders are related to, but different from :term:`path entry finders <path entry finder>`. + See :class:`importlib.abc.MetaPathFinder` for the methods that meta path + finders implement. + metaclass The class of a class. Class definitions create a class name, a class dictionary, and a list of base classes. The metaclass is responsible for @@ -549,7 +637,7 @@ Glossary module spec A namespace containing the import-related information used to load a - module. + module. An instance of :class:`importlib.machinery.ModuleSpec`. MRO See :term:`method resolution order`. @@ -676,6 +764,9 @@ Glossary (i.e. a :term:`path entry hook`) which knows how to locate modules given a :term:`path entry`. + See :class:`importlib.abc.PathEntryFinder` for the methods that path entry + finders implement. + path entry hook A callable on the :data:`sys.path_hook` list which returns a :term:`path entry finder` if it knows how to find modules on a specific :term:`path |