diff options
Diffstat (limited to 'Doc/library/optparse.rst')
| -rw-r--r-- | Doc/library/optparse.rst | 124 |
1 files changed, 99 insertions, 25 deletions
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst index 06a6ae7..87ec4de 100644 --- a/Doc/library/optparse.rst +++ b/Doc/library/optparse.rst @@ -55,9 +55,9 @@ and :mod:`optparse` will print out a brief summary of your script's options: .. code-block:: text - usage: <yourscript> [options] + Usage: <yourscript> [options] - options: + Options: -h, --help show this help message and exit -f FILE, --file=FILE write report to FILE -q, --quiet don't print status messages to stdout @@ -486,9 +486,9 @@ following to standard output: .. code-block:: text - usage: <yourscript> [options] arg1 arg2 + Usage: <yourscript> [options] arg1 arg2 - options: + Options: -h, --help show this help message and exit -v, --verbose make lots of noise [default] -q, --quiet be vewwy quiet (I'm hunting wabbits) @@ -512,7 +512,7 @@ help message: is then printed before the detailed option help. If you don't supply a usage string, :mod:`optparse` uses a bland but sensible - default: ``"usage: %prog [options]"``, which is fine if your script doesn't + default: ``"Usage: %prog [options]"``, which is fine if your script doesn't take any positional arguments. * every option defines a help string, and doesn't worry about line-wrapping--- @@ -544,12 +544,33 @@ help message: default value. If an option has no default value (or the default value is ``None``), ``%default`` expands to ``none``. +Grouping Options +++++++++++++++++ + When dealing with many options, it is convenient to group these options for better help output. An :class:`OptionParser` can contain several option groups, each of which can contain several options. -Continuing with the parser defined above, adding an :class:`OptionGroup` to a -parser is easy:: +An option group is obtained using the class :class:`OptionGroup`: + +.. class:: OptionGroup(parser, title, description=None) + + where + + * parser is the :class:`OptionParser` instance the group will be insterted in + to + * title is the group title + * description, optional, is a long description of the group + +:class:`OptionGroup` inherits from :class:`OptionContainer` (like +:class:`OptionParser`) and so the :meth:`add_option` method can be used to add +an option to the group. + +Once all the options are declared, using the :class:`OptionParser` method +:meth:`add_option_group` the group is added to the previously defined parser. + +Continuing with the parser defined in the previous section, adding an +:class:`OptionGroup` to a parser is easy:: group = OptionGroup(parser, "Dangerous Options", "Caution: use these options at your own risk. " @@ -561,20 +582,73 @@ This would result in the following help output: .. code-block:: text - usage: [options] arg1 arg2 + Usage: <yourscript> [options] arg1 arg2 + + Options: + -h, --help show this help message and exit + -v, --verbose make lots of noise [default] + -q, --quiet be vewwy quiet (I'm hunting wabbits) + -f FILE, --filename=FILE + write output to FILE + -m MODE, --mode=MODE interaction mode: novice, intermediate, or + expert [default: intermediate] + + Dangerous Options: + Caution: use these options at your own risk. It is believed that some + of them bite. + + -g Group option. + +A bit more complete example might invole using more than one group: still +extendind the previous example:: + + group = OptionGroup(parser, "Dangerous Options", + "Caution: use these options at your own risk. " + "It is believed that some of them bite.") + group.add_option("-g", action="store_true", help="Group option.") + parser.add_option_group(group) + + group = OptionGroup(parser, "Debug Options") + group.add_option("-d", "--debug", action="store_true", + help="Print debug information") + group.add_option("-s", "--sql", action="store_true", + help="Print all SQL statements executed") + group.add_option("-e", action="store_true", help="Print every action done") + parser.add_option_group(group) + +that results in the following output: + +.. code-block:: text + + Usage: <yourscript> [options] arg1 arg2 + + Options: + -h, --help show this help message and exit + -v, --verbose make lots of noise [default] + -q, --quiet be vewwy quiet (I'm hunting wabbits) + -f FILE, --filename=FILE + write output to FILE + -m MODE, --mode=MODE interaction mode: novice, intermediate, or expert + [default: intermediate] + + Dangerous Options: + Caution: use these options at your own risk. It is believed that some + of them bite. + + -g Group option. + + Debug Options: + -d, --debug Print debug information + -s, --sql Print all SQL statements executed + -e Print every action done + +Another interesting method, in particular when working programmatically with +option groups is: - options: - -h, --help show this help message and exit - -v, --verbose make lots of noise [default] - -q, --quiet be vewwy quiet (I'm hunting wabbits) - -fFILE, --file=FILE write output to FILE - -mMODE, --mode=MODE interaction mode: one of 'novice', 'intermediate' - [default], 'expert' +.. method:: OptionParser.get_option_group(opt_str) - Dangerous Options: - Caution: use of these options is at your own risk. It is believed that - some of them bite. - -g Group option. + Return, if defined, the :class:`OptionGroup` that has the title or the long + description equals to *opt_str* .. _optparse-printing-version-string: @@ -646,14 +720,14 @@ Consider the first example above, where the user passes ``4x`` to an option that takes an integer:: $ /usr/bin/foo -n 4x - usage: foo [options] + Usage: foo [options] foo: error: option -n: invalid integer value: '4x' Or, where the user fails to pass a value at all:: $ /usr/bin/foo -n - usage: foo [options] + Usage: foo [options] foo: error: -n option requires an argument @@ -1155,9 +1229,9 @@ must specify for any option using that action. .. code-block:: text - usage: foo.py [options] + Usage: foo.py [options] - options: + Options: -h, --help Show this help message and exit -v Be moderately verbose --file=FILENAME Input file to read data from @@ -1352,7 +1426,7 @@ it resolves the situation by removing ``-n`` from the earlier option's list of option strings. Now ``--dry-run`` is the only way for the user to activate that option. If the user asks for help, the help message will reflect that:: - options: + Options: --dry-run do no harm [...] -n, --noisy be noisy @@ -1368,7 +1442,7 @@ existing OptionParser:: At this point, the original ``-n``/``--dry-run`` option is no longer accessible, so :mod:`optparse` removes it, leaving this help text:: - options: + Options: [...] -n, --noisy be noisy --dry-run new dry-run option |