django-admin.py should display help output when no arguments are given

[Jeff Forcier]

Ticket #378 mentions having django-admin.py honor Unix traditions -- and yet if you invoke it with no arguments, you get a profoundly unfriendly and non-Unix-like message:

$ django-admin.py
Type 'django-admin.py help' for usage.

Compare to, say, apt-get:

$ apt-get
apt 0.7.9ubuntu17.2 for i386 compiled on Apr 17 2009 16:29:24
Usage: apt-get [options] command
       apt-get [options] install|remove pkg1 [pkg2 ...]
       apt-get [options] source pkg1 [pkg2 ...]

[...]

or git:

$ git
usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]

[...]

I'm sure I didn't need to give examples, but I felt like being thorough :)

The code related to this has not changed significantly since the 1.0.X branch -- i.e. the (tiny) patch applies cleanly to the latest 1.0.X branch checkout, as well as the latest SVN.

I'm not seeing any tests that apply to django-admin.py at all, so not including one -- please point me to the right spot if I've missed something.

[Chris Beaven]

It should still use sys.exit(1)

[Jeff Forcier]

It actually does still exit with return code of 1, see end-of-line comments added to below snippet:

        try:
            subcommand = self.argv[1]
        except IndexError:
            subcommand = 'help' # Here's what my patch changes, sets subcommand to 'help'

        if subcommand == 'help': # So this is then true
            if len(args) > 2: # This is almost definitely false
                self.fetch_command(args[2]).print_help(self.prog_name, args[2])
            else: # So we branch to here
                parser.print_lax_help()
                sys.stderr.write(self.main_help_text() + '\n')
                sys.exit(1) # And exit 1

Let me know if I'm still missing something :) (I note that we could theoretically put in logic to skip the len(args) check in this situation, which would add a bit more state -- but not sure if that's worth it.)

[Chris Beaven]

That's fine. I was only triaging the content of the patch, not actually looking at code :)

Promoted!

[Adrian Holovaty]

(In [12198]) Fixed #11842 -- django-admin.py now displays usage information if invoked with no arguments. Thanks, bitprophet