Does the argparse generate a wrong help message?

[Random832]

On Fri, Dec 27, 2019, at 23:08, jfong at ms4.hinet.net wrote:
> > > optional arguments:
> > >   -h, --help   show this help message and exit
> > >   --foo [FOO]  foo help
> > >   --goo GOO    goo help
> > >
> > > D:\Works\Python>py test.py --foo 1 --goo 2
> > > 1 ['2']
>
> So the square bracket means optional, not list? My misunderstanding:-(

To be clear, the brackets in the print output do mean a list, and it is because nargs=1 produces a list rather than the default (no nargs) which is to produce a single value. This is not normally visible to the end user (it's just a difference in how your program consumes the one mandatory argument), so it's not reflected in the help output. Square brackets in the help output mean an optional argument.