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

[Chris Angelico]

On Wed, 25 Jan 2023 at 14:42, Jach Feng <jfong at ms4.hinet.net> wrote:
> I was happy working with argparse during implement my script. To save the typing, I used a default equation for testing.
>
> sample = "-4^2+5.3*abs(-2-1)/2, abs(Abc)*(B+C)/D, (-3) * sqrt(1-(x1/7)*(y1/7)) * sqrt(abs((x0-4.5)/(y0-4)))"
> parser = argparse.ArgumentParser(description='Convert infix notation to postfix')
> parser.add_argument('infix', nargs='?', default=sample, help="....")
>

You're still not really using argparse as an argument parser. Why not
just do your own -h checking? Stop trying to use argparse for what
it's not designed for, and then wondering why it isn't doing what you
expect it to magically know.

ChrisA