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Diffstat (limited to 'Doc/glossary.rst')
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1 files changed, 31 insertions, 9 deletions
diff --git a/Doc/glossary.rst b/Doc/glossary.rst index cb7e0a2b..1d40773 100644 --- a/Doc/glossary.rst +++ b/Doc/glossary.rst @@ -265,19 +265,33 @@ Glossary advanced mathematical feature. If you're not aware of a need for them, it's almost certain you can safely ignore them. + context + This term has different meanings depending on where and how it is used. + Some common meanings: + + * The temporary state or environment established by a :term:`context + manager` via a :keyword:`with` statement. + * The collection of keyvalue bindings associated with a particular + :class:`contextvars.Context` object and accessed via + :class:`~contextvars.ContextVar` objects. Also see :term:`context + variable`. + * A :class:`contextvars.Context` object. Also see :term:`current + context`. + + context management protocol + The :meth:`~object.__enter__` and :meth:`~object.__exit__` methods called + by the :keyword:`with` statement. See :pep:`343`. + context manager - An object which controls the environment seen in a :keyword:`with` - statement by defining :meth:`~object.__enter__` and :meth:`~object.__exit__` methods. - See :pep:`343`. + An object which implements the :term:`context management protocol` and + controls the environment seen in a :keyword:`with` statement. See + :pep:`343`. context variable - A variable which can have different values depending on its context. - This is similar to Thread-Local Storage in which each execution - thread may have a different value for a variable. However, with context - variables, there may be several contexts in one execution thread and the - main usage for context variables is to keep track of variables in + A variable whose value depends on which context is the :term:`current + context`. Values are accessed via :class:`contextvars.ContextVar` + objects. Context variables are primarily used to isolate state between concurrent asynchronous tasks. - See :mod:`contextvars`. contiguous .. index:: C-contiguous, Fortran contiguous @@ -311,6 +325,14 @@ Glossary is used when necessary to distinguish this implementation from others such as Jython or IronPython. + current context + The :term:`context` (:class:`contextvars.Context` object) that is + currently used by :class:`~contextvars.ContextVar` objects to access (get + or set) the values of :term:`context variables <context variable>`. Each + thread has its own current context. Frameworks for executing asynchronous + tasks (see :mod:`asyncio`) associate each task with a context which + becomes the current context whenever the task starts or resumes execution. + decorator A function returning another function, usually applied as a function transformation using the ``@wrapper`` syntax. Common examples for |