[Python-checkins] Clarify nature of parse_args 'args' argument. (#3292)
R. David Murray
webhook-mailer at python.org
Mon Sep 4 16:17:29 EDT 2017
https://github.com/python/cpython/commit/0c7983e4adf9604d0ac93757a45d14be06c27696
commit: 0c7983e4adf9604d0ac93757a45d14be06c27696
branch: master
author: R. David Murray <rdmurray at bitdance.com>
committer: GitHub <noreply at github.com>
date: 2017-09-04T16:17:26-04:00
summary:
Clarify nature of parse_args 'args' argument. (#3292)
Patch by Paul.j3. Includes an unrelated but useful addition to the
optparse porting section.
files:
M Doc/library/argparse.rst
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 45303048174..a16aa1081d8 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -898,6 +898,8 @@ values are:
usage: PROG [-h] foo [foo ...]
PROG: error: too few arguments
+.. _`argparse.REMAINDER`:
+
* ``argparse.REMAINDER``. All the remaining command-line arguments are gathered
into a list. This is commonly useful for command line utilities that dispatch
to other command line utilities::
@@ -1324,8 +1326,11 @@ The parse_args() method
created and how they are assigned. See the documentation for
:meth:`add_argument` for details.
- By default, the argument strings are taken from :data:`sys.argv`, and a new empty
- :class:`Namespace` object is created for the attributes.
+ * args_ - List of strings to parse. The default is taken from
+ :data:`sys.argv`.
+
+ * namespace_ - An object to take the attributes. The default is a new empty
+ :class:`Namespace` object.
Option value syntax
@@ -1467,6 +1472,7 @@ unambiguous (the prefix matches a unique option)::
An error is produced for arguments that could produce more than one options.
This feature can be disabled by setting :ref:`allow_abbrev` to ``False``.
+.. _args:
Beyond ``sys.argv``
^^^^^^^^^^^^^^^^^^^
@@ -1488,6 +1494,7 @@ interactive prompt::
>>> parser.parse_args(['1', '2', '3', '4', '--sum'])
Namespace(accumulate=<built-in function sum>, integers=[1, 2, 3, 4])
+.. _namespace:
The Namespace object
^^^^^^^^^^^^^^^^^^^^
@@ -2008,7 +2015,12 @@ A partial upgrade path from :mod:`optparse` to :mod:`argparse`:
* Replace ``(options, args) = parser.parse_args()`` with ``args =
parser.parse_args()`` and add additional :meth:`ArgumentParser.add_argument`
calls for the positional arguments. Keep in mind that what was previously
- called ``options``, now in :mod:`argparse` context is called ``args``.
+ called ``options``, now in the :mod:`argparse` context is called ``args``.
+
+* Replace :meth:`optparse.OptionParser.disable_interspersed_args`
+ by setting ``nargs`` of a positional argument to `argparse.REMAINDER`_, or
+ use :meth:`~ArgumentParser.parse_known_args` to collect unparsed argument
+ strings in a separate list.
* Replace callback actions and the ``callback_*`` keyword arguments with
``type`` or ``action`` arguments.
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