From 3dee0cb6217db326e844955a7f8b424c67990557 Mon Sep 17 00:00:00 2001 From: Petr Viktorin Date: Wed, 13 Oct 2021 18:34:01 +0200 Subject: [docs] lexical_analysis: Expand the text on ``_`` (GH-28903) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Also: * Expand the discussion into its own entry. (Even before this, text on ``_`` was longet than the text on ``_*``.) * Briefly note the other common convention for `_`: naming unused variables. Co-authored-by: Brandt Bucher Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com> Co-authored-by: Łukasz Langa --- Doc/reference/lexical_analysis.rst | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/Doc/reference/lexical_analysis.rst b/Doc/reference/lexical_analysis.rst index 91ca855..4f7f001 100644 --- a/Doc/reference/lexical_analysis.rst +++ b/Doc/reference/lexical_analysis.rst @@ -385,10 +385,20 @@ classes are identified by the patterns of leading and trailing underscore characters: ``_*`` - Not imported by ``from module import *``. The special identifier ``_`` is used - in the interactive interpreter to store the result of the last evaluation; it is - stored in the :mod:`builtins` module. When not in interactive mode, ``_`` - has no special meaning and is not defined. See section :ref:`import`. + Not imported by ``from module import *``. + +``_`` + In a ``case`` pattern within a :keyword:`match` statement, ``_`` is a + :ref:`soft keyword ` that denotes a + :ref:`wildcard `. + + Separately, the interactive interpreter makes the result of the last evaluation + available in the variable ``_``. + (It is stored in the :mod:`builtins` module, alongside built-in + functions like ``print``.) + + Elsewhere, ``_`` is a regular identifier. It is often used to name + "special" items, but it is not special to Python itself. .. note:: @@ -396,6 +406,8 @@ characters: refer to the documentation for the :mod:`gettext` module for more information on this convention. + It is also commonly used for unused variables. + ``__*__`` System-defined names, informally known as "dunder" names. These names are defined by the interpreter and its implementation (including the standard library). -- cgit v0.12