'-' should be a valid flag about argparse

[GoogleCodeExporter]

Could you give me a couple test cases of what you want to work? I'm a little 
confused
by your code vs your examples. For example, 'cd -' should already work fine:

>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('dir')
>>> parser.parse_args(['-'])
Namespace(dir='-')

For the case where you use +/- alone as flags, do you want to use the + and - 
with
spaces, e.g.:

>>> # hypothetical
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('-', dest='add')
>>> parser.parse_args('- X'.split())
Namespace(add='X')

Or do you want to be able to squeeze the argument up against the +/- like this:

>>> # hypothetical
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('-')
>>> parser.parse_args('-X'.split())
Namespace(add='X')

The former is relatively easy to support. The latter would be difficult because 
'-X'
looks like a mis-typed flag. I guess it would be possible to just disable the
mis-typed flag detection if an argument like the above is added, but I'd have to
think about it more.

Original comment by [email protected] on 7 Dec 2009 at 12:09

• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

Just the former. I could see too much confusion easily arising from the use if 
there
wasn't a space in-between. Mostly I just want to be able to treat it as a 
standalone
bool flag or as the key to a subparser. I've used both forms in my scripts, but 
the
subparser form is probably more common.

Original comment by [email protected] on 7 Dec 2009 at 12:20

[GoogleCodeExporter]

Added in r84:

>>> parser = argparse.ArgumentParser(prefix_chars='+-')
>>> parser.add_argument('+', dest='add')
>>> parser.add_argument('-', dest='sub')
>>> parser.parse_args(['+', '42', '-', '3'])
Namespace(add='42', sub='3')

Original comment by [email protected] on 28 Feb 2010 at 8:08

• Changed state: Fixed