Document that parents must be fully declared before children.

What steps will reproduce the problem?

>>> parent = argparse.ArgumentParser(add_help=False)
>>> child = argparse.ArgumentParser(parents=[parent])
>>> parent.add_argument('--foo', action='store_true')
>>> child.parse_args(['--foo'])
usage: [-h]
: error: unrecognized arguments: --foo

What is the expected output? What do you see instead?

>>> child.parse_args(['--foo'])
Namespace(foo=True)

Please use labels and text to provide additional information.

It should be documented clearly that only the arguments present on the
parent parser at the time ArgumentParser is called will be included in the
parser.

Original issue reported on code.google.com by steven.b...@gmail.com on 2 Mar 2010 at 7:51

yiwangai1983 / argparse

Document that parents must be fully declared before children. #61