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Diffstat (limited to 'Doc/library/argparse.rst')
| -rw-r--r-- | Doc/library/argparse.rst | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst index ec212d5..a30a8c4 100644 --- a/Doc/library/argparse.rst +++ b/Doc/library/argparse.rst @@ -203,8 +203,8 @@ argument to :class:`ArgumentParser`. add_help ^^^^^^^^ -By default, ArgumentParser objects add a ``-h/--help`` option which simply -displays the parser's help message. For example, consider a file named +By default, ArgumentParser objects add an option which simply displays +the parser's help message. For example, consider a file named ``myprogram.py`` containing the following code:: import argparse @@ -234,12 +234,27 @@ This can be achieved by passing ``False`` as the ``add_help=`` argument to optional arguments: --foo FOO foo help +The help option is typically ``-h/--help``. The exception to this is +if the ``prefix_chars=`` is specified and does not include ``'-'``, in +which case ``-h`` and ``--help`` are not valid options. In +this case, the first character in ``prefix_chars`` is used to prefix +the help options:: + + >>> parser = argparse.ArgumentParser(prog='PROG', prefix_chars='+/') + >>> parser.print_help() + usage: PROG [+h] + + optional arguments: + +h, ++help show this help message and exit + + prefix_chars ^^^^^^^^^^^^ Most command-line options will use ``'-'`` as the prefix, e.g. ``-f/--foo``. -Parsers that need to support additional prefix characters, e.g. for options +Parsers that need to support different or additional prefix +characters, e.g. for options like ``+f`` or ``/foo``, may specify them using the ``prefix_chars=`` argument to the ArgumentParser constructor:: |