class documentation

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 __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 opt_help Display this help and exit.
Method opt_version Display Twisted version and exit.
Method parseArgs I am called with any leftover arguments which were not options.
Method parseOptions The guts of the command-line parser.
Method postOptions I am called after the options are parsed.
Class Variable completionData Undocumented
Class Variable defaultSubCommand Undocumented
Class Variable parent Undocumented
Instance Variable defaults Undocumented
Instance Variable docs Undocumented
Instance Variable longOpt Undocumented
Instance Variable opts Undocumented
Instance Variable shortOpt Undocumented
Instance Variable subCommand Undocumented
Instance Variable subOptions Undocumented
Instance Variable synonyms Undocumented
Method _gather_flags Gather up boolean (flag) options.
Method _gather_handlers Gather up options with their own handler methods.
Method _gather_parameters Gather options which take a value.
Method _generic_flag Undocumented
Instance Variable _dispatch Undocumented
def __str__(self) -> str: (source)

Undocumented

def getSynopsis(self) -> str: (source)

Returns a string containing a description of these options and how to pass them to the executed file.

def getUsage(self, width: Optional[int] = None) -> str: (source)

Undocumented

def opt_help(self): (source)

Display this help and exit.

def parseArgs(self): (source)

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!

def parseOptions(self, options=None): (source)
def postOptions(self): (source)

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.

completionData = (source)

Undocumented

defaultSubCommand: Optional[str] = (source)

Undocumented

Undocumented

defaults: dict = (source)

Undocumented

Undocumented

Undocumented

Undocumented

shortOpt = (source)

Undocumented

Undocumented

subOptions = (source)

Undocumented

synonyms: dict = (source)

Undocumented

def _gather_flags(self): (source)

Gather up boolean (flag) options.

def _gather_handlers(self): (source)

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.

def _gather_parameters(self): (source)

Gather options which take a value.

def _generic_flag(self, flagName, value=None): (source)

Undocumented

_dispatch: dict = (source)

Undocumented