How to make argparse accept "-4^2+5.3*abs(-2-1)/2" string argument?

[Jach Feng]

cameron... at gmail.com 在 2023年1月24日 星期二下午2:05:33 [UTC+8] 的信中寫道：
> On 23Jan2023 17:58, Jach Feng <jf... at ms4.hinet.net> wrote: 
> >>>> parser.parse_args(['--', 'infix2postfix.py', '-4.3+5']) 
> >usage: [-h] infix 
> >: error: unrecognized arguments: -4.3+5
> This error doesn't look like "-4.3+5 looks like an option" but instead 
> "we don't expect any arguments after "infix". 
> 
> Not personally a fan of argparse myself, but then I have my own 
> elaborate command line framework which generally uses getopt for the 
> option stuff. 
> 
> Cheers, 
> Cameron Simpson <c... at cskk.id.au>
Hmm, good to you. During experiments in these days, I had found argparse shows some strange/unstable behaviors in dealing with the leading '-' situation.