[issue9444] argparse does not honor prefix_chars when adding default options

[Doug Hellmann]

New submission from Doug Hellmann <doug.hellmann at gmail.com>:

If an ArgumentParser is created with a prefix_chars string that does not include '-', the default options created for showing help (-h and --help) and the version (-v and --version) are invalid and generate an exception.

----------
components: Library (Lib)
files: argparse_prefix_chars_bug.py
messages: 112219
nosy: doughellmann
priority: normal
severity: normal
status: open
title: argparse does not honor prefix_chars when adding default options
versions: Python 2.7
Added file: http://bugs.python.org/file18292/argparse_prefix_chars_bug.py

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue9444>
_______________________________________