[Python-Dev] PEP 389: argparse - new command line parsing module

[Paul Moore]

2009/9/28 Yuvgoog Greenle <ubershmekel at gmail.com>:
> 1. There is no chance of the script killing itself. In argparse and optparse
> exit() is called on every parsing error (btw because of this it sucks to
> debug parse_args in an interpreter).

That one does worry me. I'd rather argparse (or any library function)
didn't call sys.exit on my behalf - it should raise an exception. Is
it actually true that argparse exits? (I can imagine that it might if
--help was specified, for example. An exception may not be right here,
but I still don't like the idea of a straight exit - I've used too
many C libraries that think they know when I want to exit).

> 2. There is no chance the parser will print things I don't want it to print.

That may also be bad - for example, Windows GUI-mode programs raise an
error if they write to stdout/stderr. I could imagine using argparse
for such a program, and wanting to do something with --help other than
write to stdout and exit (a message box, for example). And yet, I'd
want access to the text argparse would otherwise write to stdout.

Paul.