[Python-checkins] cpython: Closes #12713: Allowed abbreviation of subcommands in argparse.
vinay.sajip
python-checkins at python.org
Thu Aug 18 16:24:28 EDT 2016
https://hg.python.org/cpython/rev/97b28115bd08
changeset: 102743:97b28115bd08
user: Vinay Sajip <vinay_sajip at yahoo.co.uk>
date: Thu Aug 18 21:23:48 2016 +0100
summary:
Closes #12713: Allowed abbreviation of subcommands in argparse.
files:
Doc/library/argparse.rst | 12 +++
Lib/argparse.py | 23 +++++-
Lib/test/test_argparse.py | 92 +++++++++++++++++++-------
3 files changed, 95 insertions(+), 32 deletions(-)
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -1668,6 +1668,18 @@
>>> parser.parse_args(['co', 'bar'])
Namespace(foo='bar')
+ argparse supports non-ambiguous abbreviations of subparser names.
+
+ For example, the following three calls are all supported
+ and do the same thing, as the abbreviations used are not ambiguous::
+
+ >>> parser.parse_args(['checkout', 'bar'])
+ Namespace(foo='bar')
+ >>> parser.parse_args(['check', 'bar'])
+ Namespace(foo='bar')
+ >>> parser.parse_args(['che', 'bar'])
+ Namespace(foo='bar')
+
One particularly effective way of handling sub-commands is to combine the use
of the :meth:`add_subparsers` method with calls to :meth:`set_defaults` so
that each subparser knows which Python function it should execute. For
diff --git a/Lib/argparse.py b/Lib/argparse.py
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1110,6 +1110,12 @@
parser_name = values[0]
arg_strings = values[1:]
+ # get full parser_name from (optional) abbreviated one
+ for p in self._name_parser_map:
+ if p.startswith(parser_name):
+ parser_name = p
+ break
+
# set the parser name if requested
if self.dest is not SUPPRESS:
setattr(namespace, self.dest, parser_name)
@@ -2307,11 +2313,18 @@
def _check_value(self, action, value):
# converted value must be one of the choices (if specified)
- if action.choices is not None and value not in action.choices:
- args = {'value': value,
- 'choices': ', '.join(map(repr, action.choices))}
- msg = _('invalid choice: %(value)r (choose from %(choices)s)')
- raise ArgumentError(action, msg % args)
+ if action.choices is not None:
+ ac = [ax for ax in action.choices if str(ax).startswith(str(value))]
+ if len(ac) == 0:
+ args = {'value': value,
+ 'choices': ', '.join(map(repr, action.choices))}
+ msg = _('invalid choice: %(value)r (choose from %(choices)s)')
+ raise ArgumentError(action, msg % args)
+ elif len(ac) > 1:
+ args = {'value': value,
+ 'choices': ', '.join(ac)}
+ msg = _('ambiguous choice: %(value)r could match %(choices)s')
+ raise ArgumentError(action, msg % args)
# =======================
# Help-formatting methods
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -1842,6 +1842,22 @@
parser3.add_argument('t', type=int, help='t help')
parser3.add_argument('u', nargs='...', help='u help')
+ # add fourth sub-parser (to test abbreviations)
+ parser4_kwargs = dict(description='lost description')
+ if subparser_help:
+ parser4_kwargs['help'] = 'lost help'
+ parser4 = subparsers.add_parser('lost', **parser4_kwargs)
+ parser4.add_argument('-w', type=int, help='w help')
+ parser4.add_argument('x', choices='abc', help='x help')
+
+ # add fifth sub-parser, with longer name (to test abbreviations)
+ parser5_kwargs = dict(description='long description')
+ if subparser_help:
+ parser5_kwargs['help'] = 'long help'
+ parser5 = subparsers.add_parser('long', **parser5_kwargs)
+ parser5.add_argument('-w', type=int, help='w help')
+ parser5.add_argument('x', choices='abc', help='x help')
+
# return the main parser
return parser
@@ -1857,6 +1873,24 @@
args = args_str.split()
self.assertArgumentParserError(self.parser.parse_args, args)
+ def test_parse_args_abbreviation(self):
+ # check some non-failure cases:
+ self.assertEqual(
+ self.parser.parse_args('0.5 long b -w 7'.split()),
+ NS(foo=False, bar=0.5, w=7, x='b'),
+ )
+ self.assertEqual(
+ self.parser.parse_args('0.5 lon b -w 7'.split()),
+ NS(foo=False, bar=0.5, w=7, x='b'),
+ )
+ self.assertEqual(
+ self.parser.parse_args('0.5 los b -w 7'.split()),
+ NS(foo=False, bar=0.5, w=7, x='b'),
+ )
+ # check a failure case: 'lo' is ambiguous
+ self.assertArgumentParserError(self.parser.parse_args,
+ '0.5 lo b -w 7'.split())
+
def test_parse_args(self):
# check some non-failure cases:
self.assertEqual(
@@ -1909,78 +1943,80 @@
def test_help(self):
self.assertEqual(self.parser.format_usage(),
- 'usage: PROG [-h] [--foo] bar {1,2,3} ...\n')
+ 'usage: PROG [-h] [--foo] bar {1,2,3,lost,long} ...\n')
self.assertEqual(self.parser.format_help(), textwrap.dedent('''\
- usage: PROG [-h] [--foo] bar {1,2,3} ...
+ usage: PROG [-h] [--foo] bar {1,2,3,lost,long} ...
main description
positional arguments:
- bar bar help
- {1,2,3} command help
+ bar bar help
+ {1,2,3,lost,long} command help
optional arguments:
- -h, --help show this help message and exit
- --foo foo help
+ -h, --help show this help message and exit
+ --foo foo help
'''))
def test_help_extra_prefix_chars(self):
# Make sure - is still used for help if it is a non-first prefix char
parser = self._get_parser(prefix_chars='+:-')
self.assertEqual(parser.format_usage(),
- 'usage: PROG [-h] [++foo] bar {1,2,3} ...\n')
+ 'usage: PROG [-h] [++foo] bar {1,2,3,lost,long} ...\n')
self.assertEqual(parser.format_help(), textwrap.dedent('''\
- usage: PROG [-h] [++foo] bar {1,2,3} ...
+ usage: PROG [-h] [++foo] bar {1,2,3,lost,long} ...
main description
positional arguments:
- bar bar help
- {1,2,3} command help
+ bar bar help
+ {1,2,3,lost,long} command help
optional arguments:
- -h, --help show this help message and exit
- ++foo foo help
+ -h, --help show this help message and exit
+ ++foo foo help
'''))
def test_help_alternate_prefix_chars(self):
parser = self._get_parser(prefix_chars='+:/')
self.assertEqual(parser.format_usage(),
- 'usage: PROG [+h] [++foo] bar {1,2,3} ...\n')
+ 'usage: PROG [+h] [++foo] bar {1,2,3,lost,long} ...\n')
self.assertEqual(parser.format_help(), textwrap.dedent('''\
- usage: PROG [+h] [++foo] bar {1,2,3} ...
+ usage: PROG [+h] [++foo] bar {1,2,3,lost,long} ...
main description
positional arguments:
- bar bar help
- {1,2,3} command help
+ bar bar help
+ {1,2,3,lost,long} command help
optional arguments:
- +h, ++help show this help message and exit
- ++foo foo help
+ +h, ++help show this help message and exit
+ ++foo foo help
'''))
def test_parser_command_help(self):
self.assertEqual(self.command_help_parser.format_usage(),
- 'usage: PROG [-h] [--foo] bar {1,2,3} ...\n')
+ 'usage: PROG [-h] [--foo] bar {1,2,3,lost,long} ...\n')
self.assertEqual(self.command_help_parser.format_help(),
textwrap.dedent('''\
- usage: PROG [-h] [--foo] bar {1,2,3} ...
+ usage: PROG [-h] [--foo] bar {1,2,3,lost,long} ...
main description
positional arguments:
- bar bar help
- {1,2,3} command help
- 1 1 help
- 2 2 help
- 3 3 help
+ bar bar help
+ {1,2,3,lost,long} command help
+ 1 1 help
+ 2 2 help
+ 3 3 help
+ lost lost help
+ long long help
optional arguments:
- -h, --help show this help message and exit
- --foo foo help
+ -h, --help show this help message and exit
+ --foo foo help
'''))
def test_subparser_title_help(self):
@@ -2083,6 +2119,8 @@
1 help
2 2 help
3 3 help
+ lost lost help
+ long long help
"""))
# ============
--
Repository URL: https://hg.python.org/cpython
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