Say I have an argument with the name 'foo-bar'.  Argparse accepts and parses arguments, but Namespace does not allow me to access the value.

Yes, I can use getattr or Namespace.__dict__.  But that's ugly.
Yes, I can change the name of the argument, but that's not what I want in my help output.

I think it should either:
- Collapse names to valid python identifiers (optparse did this).
- Namespace should act like an object and dict.

If argparse munged foo-bar to foo_bar to allow attribute access, then it’d need to disallow ambiguous cases like add_argument('foo_bar', ...); add_argument('foo-bar', ...).  I’m not sure if there is real, sensible code that does that, though.

> Namespace should act like an object and dict.
I don’t understand, can you rephrase?

For optional flags like --foo-bar, argparse does munge the "dest" to "foo_bar", following optparse. For positional arguments, arpgarse doesn't munge things this way, but if you want the argument named "foo-bar" in help messages and "foo_bar" on the Namespace object, you just need to do something like:

add_argument('foo_bar', metavar='foo-bar', ...)

Perhaps the docs could make this clearer.

> I don’t understand, can you rephrase?

Sorry, I mean making Namespace subscriptable.  eg:

>>> v = argparse.Namespace(abc = 123)
>>> v
Namespace(abc=123)
>>> v.abc
123
>>> v['abc']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'Namespace' object is not subscriptable

> add_argument('foo_bar', metavar='foo-bar', ...)

This works. Thanks!

Cheers,
Joe

> making Namespace subscriptable

This has been discussed before - see issue 11076. I prefer to keep Namespace as simple as possible. For subscripting, just use the standard Python idiom of vars as suggested in the docs:

http://docs.python.org/library/argparse.html#the-namespace-object

#11076 was closed as a duplicate of #8982 which was closed as fixed so can this also be closed as a duplicate?

Hi everyone!

I thought to take this issue up by updating the documentation. Is this still relevant?

If so I think the best place to add the documentation is in the "name or flags" section, where people will go looking first. I think to add both the metavar and the vars solutions discussed below.

I think this one should have been closed long ago.