Merge pull request #23 from catb0t/args

xo.main: allow specifying options like -v without needing a path

xo.py

@@ -30,7 +30,7 @@
 from itertools import zip_longest
 from collections import deque
 from collections.abc import Mapping, Sequence
-from argparse import ArgumentParser, RawDescriptionHelpFormatter
+from argparse import ArgumentParser, RawDescriptionHelpFormatter, _StoreTrueAction
 
 import urwid
 import pygments.util
@@ -981,15 +981,21 @@ def main(args=None):
  main_display = MainDisplay()
  parser = ArgumentParser(prog='xo', formatter_class=RawDescriptionHelpFormatter,
  description=__doc__.format(**main_display.keybindings))
- parser.add_argument('path', nargs='?',
- help=("path to file, may include colon separated "
- "line and col numbers, eg 'path/to/xo.py:10:42'"))
- parser.add_argument('--rc', default=False, action="store_true",
+ path = parser.add_argument('path', help=("path to file, may include colon separated "
+ "line and col numbers, eg 'path/to/xo.py:10:42'"))
+
+ class EitherOrAction(_StoreTrueAction):
+ def __call__(self, parser, namespace, values, option_string=None):
+ setattr(namespace, self.dest, self.const)
+ path.required = False
+
+ parser.add_argument('--rc', action=EitherOrAction,
  help="display run control file")
- parser.add_argument('--rc-edit', default=False, action="store_true",
+ parser.add_argument('--rc-edit', action=EitherOrAction,
  help="open run control file")
- parser.add_argument('-v', '--version', default=False, action="store_true",
+ parser.add_argument('-v', '--version', action=EitherOrAction,
  help="show version and exit")
+
  ns = parser.parse_args(args=args)
  if ns.version:
  print("{} v{}".format('xo', __version__))