twisted.python.usage.Options(dict)
class documentationtwisted.python.usage
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Known subclasses: twisted.application.app.ServerOptions, twisted.application.twist._options.TwistOptions, twisted.conch.client.options.ConchOptions, twisted.conch.manhole_tap.Options, twisted.conch.scripts.ckeygen.GeneralOptions, twisted.conch.scripts.tkconch.GeneralOptions, twisted.conch.tap.Options, twisted.mail.tap.Options, twisted.names.tap.Options, twisted.news.tap.DBOptions, twisted.news.tap.Options, twisted.news.tap.PickleOptions, twisted.runner.inetdtap.Options, twisted.runner.procmontap.Options, twisted.scripts.htmlizer.Options, twisted.scripts.trial.Options, twisted.tap.ftp.Options, twisted.tap.portforward.Options, twisted.tap.socks.Options, twisted.trial._dist.options.WorkerOptions, twisted.web.tap.Options, twisted.words.tap.Options, twisted.words.xmpproutertap.Options
An option list parser class
optFlags
and optParameters
are lists of
available parameters which your program can handle. The difference between
the two is the 'flags' have an on(1) or off(0) state (off by default)
whereas 'parameters' have an assigned value, with an optional default.
(Compare '--verbose' and '--verbosity=2')
optFlags is assigned a list of lists. Each list represents a flag parameter, as so:
optFlags = [['verbose', 'v', 'Makes it tell you what it doing.'], ['quiet', 'q', 'Be vewy vewy quiet.']]
As you can see, the first item is the long option name (prefixed with '--' on the command line), followed by the short option name (prefixed with '-'), and the description. The description is used for the built-in handling of the --help switch, which prints a usage summary.
optParameters
is much the same, except the list also
contains a default value:
optParameters = [['outfile', 'O', 'outfile.log', 'Description...']]
A coerce function can also be specified as the last element: it will be
called with the argument and should return the value that will be stored
for the option. This function can have a coerceDoc
attribute
which will be appended to the documentation of the option.
subCommands is a list of 4-tuples of (command name, command shortcut, parser class, documentation). If the first non-option argument found is one of the given command names, an instance of the given parser class is instantiated and given the remainder of the arguments to parse and self.opts[command] is set to the command name. For example:
subCommands = [ ['inquisition', 'inquest', InquisitionOptions, 'Perform an inquisition'], ['holyquest', 'quest', HolyQuestOptions, 'Embark upon a holy quest'] ]
In this case, "<program> holyquest --horseback
--for-grail"
will cause HolyQuestOptions
to be
instantiated and asked to parse ['--horseback',
'--for-grail']
. Currently, only the first sub-command is parsed,
and all options following it are passed to its parser. If a subcommand is
found, the subCommand attribute is set to its name and the subOptions
attribute is set to the Option instance that parses the remaining options.
If a subcommand is not given to parseOptions, the subCommand attribute will
be None. You can also mark one of the subCommands to be the default:
defaultSubCommand = 'holyquest'
In this case, the subCommand attribute will never be None, and the subOptions attribute will always be set.
If you want to handle your own options, define a method named
opt_paramname
that takes (self, option)
as
arguments. option
will be whatever immediately follows the
parameter on the command line. Options fully supports the mapping
interface, so you can do things like 'self["option"] =
val'
in these methods.
Shell tab-completion is supported by this class, for zsh only at
present. Zsh ships with a stub file ("completion function")
which, for Twisted commands, performs tab-completion on-the-fly using the
support provided by this class. The stub file lives in our tree at
twisted/python/twisted-completion.zsh
, and in the Zsh tree at
Completion/Unix/Command/_twisted
.
Tab-completion is based upon the contents of the optFlags and
optParameters lists. And, optionally, additional metadata may be provided
by assigning a special attribute, compData
, which should be an
instance of Completions
. See that class for details of what
can and should be included - and see the howto for additional help using
these features - including how third-parties may take advantage of
tab-completion for their own commands.
Advanced functionality is covered in the howto documentation, available at http://twistedmatrix.com/projects/core/documentation/howto/options.html, or doc/core/howto/options.xhtml in your Twisted directory.
Method | __init__ | Undocumented |
Method | opt_help | Display this help and exit. |
Method | opt_version | Display Twisted version and exit. |
Method | parseOptions | The guts of the command-line parser. |
Method | postOptions | I am called after the options are parsed. |
Method | parseArgs | I am called with any leftover arguments which were not options. |
Method | __str__ | Undocumented |
Method | getSynopsis | Returns a string containing a description of these options and how to pass them to the executed file. |
Method | getUsage | Undocumented |
Method | _generic_flag | Undocumented |
Method | _gather_flags | Gather up boolean (flag) options. |
Method | _gather_parameters | Gather options which take a value. |
Method | _gather_handlers | Gather up options with their own handler methods. |
Display Twisted version and exit.
The guts of the command-line parser.
I am called after the options are parsed.
Override this method in your subclass to do something after the options have been parsed and assigned, like validate that all options are sane.
I am called with any leftover arguments which were not options.
Override me to do something with the remaining arguments on the command line, those which were not flags or options. e.g. interpret them as a list of files to operate on.
Note that if there more arguments on the command line than this method accepts, parseArgs will blow up with a getopt.error. This means if you don't override me, parseArgs will blow up if I am passed any arguments at all!
Gather up options with their own handler methods.
This returns a tuple of many values. Amongst those values is a synonyms
dictionary, mapping all of the possible aliases (str
) for an
option to the longest spelling of that option's name C({str}).
Another element is a dispatch dictionary, mapping each user-facing option name (with - substituted for _) to a callable to handle that option.
Returns a string containing a description of these options and how to pass them to the executed file.