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-% THIS FILE IS AUTO-GENERATED!  DO NOT EDIT!
-% (Your changes will be lost the next time it is generated.)
-\section{\module{optparse} --- More powerful command line option parser}
-\declaremodule{standard}{optparse}
-\moduleauthor{Greg Ward}{gward@python.net}
-\modulesynopsis{More convenient, flexible, and powerful command-line parsing library.}
-\versionadded{2.3}
-\sectionauthor{Greg Ward}{gward@python.net}
-% An intro blurb used only when generating LaTeX docs for the Python
-% manual (based on README.txt). 
-
-\code{optparse} is a more convenient, flexible, and powerful library for
-parsing command-line options than \code{getopt}.  \code{optparse} uses a more
-declarative style of command-line parsing: you create an instance of
-\class{OptionParser}, populate it with options, and parse the command line.
-\code{optparse} allows users to specify options in the conventional GNU/POSIX
-syntax, and additionally generates usage and help messages for you.
-
-Here's an example of using \code{optparse} in a simple script:
-\begin{verbatim}
-from optparse import OptionParser
-[...]
-parser = OptionParser()
-parser.add_option("-f", "--file", dest="filename",
-                  help="write report to FILE", metavar="FILE")
-parser.add_option("-q", "--quiet",
-                  action="store_false", dest="verbose", default=True,
-                  help="don't print status messages to stdout")
-
-(options, args) = parser.parse_args()
-\end{verbatim}
-
-With these few lines of code, users of your script can now do the
-``usual thing'' on the command-line, for example:
-\begin{verbatim}
-<yourscript> --file=outfile -q
-\end{verbatim}
-
-As it parses the command line, \code{optparse} sets attributes of the
-\code{options} object returned by \method{parse{\_}args()} based on user-supplied
-command-line values.  When \method{parse{\_}args()} returns from parsing this
-command line, \code{options.filename} will be \code{"outfile"} and
-\code{options.verbose} will be \code{False}.  \code{optparse} supports both long
-and short options, allows short options to be merged together, and
-allows options to be associated with their arguments in a variety of
-ways.  Thus, the following command lines are all equivalent to the above
-example:
-\begin{verbatim}
-<yourscript> -f outfile --quiet
-<yourscript> --quiet --file outfile
-<yourscript> -q -foutfile
-<yourscript> -qfoutfile
-\end{verbatim}
-
-Additionally, users can run one of
-\begin{verbatim}
-<yourscript> -h
-<yourscript> --help
-\end{verbatim}
-
-and \code{optparse} will print out a brief summary of your script's
-options:
-\begin{verbatim}
-usage: <yourscript> [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
-\end{verbatim}
-
-where the value of \emph{yourscript} is determined at runtime (normally
-from \code{sys.argv{[}0]}).
-% $Id: intro.txt 413 2004-09-28 00:59:13Z greg $ 
-
-
-\subsection{Background\label{optparse-background}}
-
-\module{optparse} was explicitly designed to encourage the creation of programs with
-straightforward, conventional command-line interfaces.  To that end, it
-supports only the most common command-line syntax and semantics
-conventionally used under \UNIX{}.  If you are unfamiliar with these
-conventions, read this section to acquaint yourself with them.
-
-
-\subsubsection{Terminology\label{optparse-terminology}}
-\begin{description}
-\item[argument]
-a string entered on the command-line, and passed by the shell to
-\code{execl()} or \code{execv()}.  In Python, arguments are elements of
-\code{sys.argv{[}1:]} (\code{sys.argv{[}0]} is the name of the program being
-executed).  \UNIX{} shells also use the term ``word''.
-
-It is occasionally desirable to substitute an argument list other
-than \code{sys.argv{[}1:]}, so you should read ``argument'' as ``an element of
-\code{sys.argv{[}1:]}, or of some other list provided as a substitute for
-\code{sys.argv{[}1:]}''.
-\item[option   ]
-an argument used to supply extra information to guide or customize the
-execution of a program.  There are many different syntaxes for
-options; the traditional \UNIX{} syntax is a hyphen (``-'') followed by a
-single letter, e.g. \code{"-x"} or \code{"-F"}.  Also, traditional \UNIX{}
-syntax allows multiple options to be merged into a single argument,
-e.g.  \code{"-x -F"} is equivalent to \code{"-xF"}.  The GNU project
-introduced \code{"-{}-"} followed by a series of hyphen-separated words,
-e.g. \code{"-{}-file"} or \code{"-{}-dry-run"}.  These are the only two option
-syntaxes provided by \module{optparse}.
-
-Some other option syntaxes that the world has seen include:
-\begin{itemize}
-\item {} 
-a hyphen followed by a few letters, e.g. \code{"-pf"} (this is
-\emph{not} the same as multiple options merged into a single argument)
-
-\item {} 
-a hyphen followed by a whole word, e.g. \code{"-file"} (this is
-technically equivalent to the previous syntax, but they aren't
-usually seen in the same program)
-
-\item {} 
-a plus sign followed by a single letter, or a few letters,
-or a word, e.g. \code{"+f"}, \code{"+rgb"}
-
-\item {} 
-a slash followed by a letter, or a few letters, or a word, e.g.
-\code{"/f"}, \code{"/file"}
-
-\end{itemize}
-
-These option syntaxes are not supported by \module{optparse}, and they never will
-be.  This is deliberate: the first three are non-standard on any
-environment, and the last only makes sense if you're exclusively
-targeting VMS, MS-DOS, and/or Windows.
-\item[option argument]
-an argument that follows an option, is closely associated with that
-option, and is consumed from the argument list when that option is.
-With \module{optparse}, option arguments may either be in a separate argument
-from their option:
-\begin{verbatim}
--f foo
---file foo
-\end{verbatim}
-
-or included in the same argument:
-\begin{verbatim}
--ffoo
---file=foo
-\end{verbatim}
-
-Typically, a given option either takes an argument or it doesn't.
-Lots of people want an ``optional option arguments'' feature, meaning
-that some options will take an argument if they see it, and won't if
-they don't.  This is somewhat controversial, because it makes parsing
-ambiguous: if \code{"-a"} takes an optional argument and \code{"-b"} is
-another option entirely, how do we interpret \code{"-ab"}?  Because of
-this ambiguity, \module{optparse} does not support this feature.
-\item[positional argument]
-something leftover in the argument list after options have been
-parsed, i.e. after options and their arguments have been parsed and
-removed from the argument list.
-\item[required option]
-an option that must be supplied on the command-line; note that the
-phrase ``required option'' is self-contradictory in English.  \module{optparse}
-doesn't prevent you from implementing required options, but doesn't
-give you much help at it either.  See \code{examples/required{\_}1.py} and
-\code{examples/required{\_}2.py} in the \module{optparse} source distribution for two
-ways to implement required options with \module{optparse}.
-\end{description}
-
-For example, consider this hypothetical command-line:
-\begin{verbatim}
-prog -v --report /tmp/report.txt foo bar
-\end{verbatim}
-
-\code{"-v"} and \code{"-{}-report"} are both options.  Assuming that
-\longprogramopt{report} takes one argument, \code{"/tmp/report.txt"} is an option
-argument.  \code{"foo"} and \code{"bar"} are positional arguments.
-
-
-\subsubsection{What are options for?\label{optparse-what-options-for}}
-
-Options are used to provide extra information to tune or customize the
-execution of a program.  In case it wasn't clear, options are usually
-\emph{optional}.  A program should be able to run just fine with no options
-whatsoever.  (Pick a random program from the \UNIX{} or GNU toolsets.  Can
-it run without any options at all and still make sense?  The main
-exceptions are \code{find}, \code{tar}, and \code{dd}{---}all of which are mutant
-oddballs that have been rightly criticized for their non-standard syntax
-and confusing interfaces.)
-
-Lots of people want their programs to have ``required options''.  Think
-about it.  If it's required, then it's \emph{not optional}!  If there is a
-piece of information that your program absolutely requires in order to
-run successfully, that's what positional arguments are for.
-
-As an example of good command-line interface design, consider the humble
-\code{cp} utility, for copying files.  It doesn't make much sense to try to
-copy files without supplying a destination and at least one source.
-Hence, \code{cp} fails if you run it with no arguments.  However, it has a
-flexible, useful syntax that does not require any options at all:
-\begin{verbatim}
-cp SOURCE DEST
-cp SOURCE ... DEST-DIR
-\end{verbatim}
-
-You can get pretty far with just that.  Most \code{cp} implementations
-provide a bunch of options to tweak exactly how the files are copied:
-you can preserve mode and modification time, avoid following symlinks,
-ask before clobbering existing files, etc.  But none of this distracts
-from the core mission of \code{cp}, which is to copy either one file to
-another, or several files to another directory.
-
-
-\subsubsection{What are positional arguments for?\label{optparse-what-positional-arguments-for}}
-
-Positional arguments are for those pieces of information that your
-program absolutely, positively requires to run.
-
-A good user interface should have as few absolute requirements as
-possible.  If your program requires 17 distinct pieces of information in
-order to run successfully, it doesn't much matter \emph{how} you get that
-information from the user{---}most people will give up and walk away
-before they successfully run the program.  This applies whether the user
-interface is a command-line, a configuration file, or a GUI: if you make
-that many demands on your users, most of them will simply give up.
-
-In short, try to minimize the amount of information that users are
-absolutely required to supply{---}use sensible defaults whenever
-possible.  Of course, you also want to make your programs reasonably
-flexible.  That's what options are for.  Again, it doesn't matter if
-they are entries in a config file, widgets in the ``Preferences'' dialog
-of a GUI, or command-line options{---}the more options you implement, the
-more flexible your program is, and the more complicated its
-implementation becomes.  Too much flexibility has drawbacks as well, of
-course; too many options can overwhelm users and make your code much
-harder to maintain.
-% $Id: tao.txt 413 2004-09-28 00:59:13Z greg $ 
-
-
-\subsection{Tutorial\label{optparse-tutorial}}
-
-While \module{optparse} is quite flexible and powerful, it's also straightforward to
-use in most cases.  This section covers the code patterns that are
-common to any \module{optparse}-based program.
-
-First, you need to import the OptionParser class; then, early in the
-main program, create an OptionParser instance:
-\begin{verbatim}
-from optparse import OptionParser
-[...]
-parser = OptionParser()
-\end{verbatim}
-
-Then you can start defining options.  The basic syntax is:
-\begin{verbatim}
-parser.add_option(opt_str, ...,
-                  attr=value, ...)
-\end{verbatim}
-
-Each option has one or more option strings, such as \code{"-f"} or
-\code{"-{}-file"}, and several option attributes that tell \module{optparse} what to
-expect and what to do when it encounters that option on the command
-line.
-
-Typically, each option will have one short option string and one long
-option string, e.g.:
-\begin{verbatim}
-parser.add_option("-f", "--file", ...)
-\end{verbatim}
-
-You're free to define as many short option strings and as many long
-option strings as you like (including zero), as long as there is at
-least one option string overall.
-
-The option strings passed to \method{add{\_}option()} are effectively labels for
-the option defined by that call.  For brevity, we will frequently refer
-to \emph{encountering an option} on the command line; in reality, \module{optparse}
-encounters \emph{option strings} and looks up options from them.
-
-Once all of your options are defined, instruct \module{optparse} to parse your
-program's command line:
-\begin{verbatim}
-(options, args) = parser.parse_args()
-\end{verbatim}
-
-(If you like, you can pass a custom argument list to \method{parse{\_}args()},
-but that's rarely necessary: by default it uses \code{sys.argv{[}1:]}.)
-
-\method{parse{\_}args()} returns two values:
-\begin{itemize}
-\item {} 
-\code{options}, an object containing values for all of your options{---}e.g. if \code{"-{}-file"} takes a single string argument, then
-\code{options.file} will be the filename supplied by the user, or
-\code{None} if the user did not supply that option
-
-\item {} 
-\code{args}, the list of positional arguments leftover after parsing
-options
-
-\end{itemize}
-
-This tutorial section only covers the four most important option
-attributes: \member{action}, \member{type}, \member{dest} (destination), and \member{help}.
-Of these, \member{action} is the most fundamental.
-
-
-\subsubsection{Understanding option actions\label{optparse-understanding-option-actions}}
-
-Actions tell \module{optparse} what to do when it encounters an option on the
-command line.  There is a fixed set of actions hard-coded into \module{optparse};
-adding new actions is an advanced topic covered in section~\ref{optparse-extending-optparse}, Extending \module{optparse}.
-Most actions tell \module{optparse} to store a value in some variable{---}for
-example, take a string from the command line and store it in an
-attribute of \code{options}.
-
-If you don't specify an option action, \module{optparse} defaults to \code{store}.
-
-
-\subsubsection{The store action\label{optparse-store-action}}
-
-The most common option action is \code{store}, which tells \module{optparse} to take
-the next argument (or the remainder of the current argument), ensure
-that it is of the correct type, and store it to your chosen destination.
-
-For example:
-\begin{verbatim}
-parser.add_option("-f", "--file",
-                  action="store", type="string", dest="filename")
-\end{verbatim}
-
-Now let's make up a fake command line and ask \module{optparse} to parse it:
-\begin{verbatim}
-args = ["-f", "foo.txt"]
-(options, args) = parser.parse_args(args)
-\end{verbatim}
-
-When \module{optparse} sees the option string \code{"-f"}, it consumes the next
-argument, \code{"foo.txt"}, and stores it in \code{options.filename}.  So,
-after this call to \method{parse{\_}args()}, \code{options.filename} is
-\code{"foo.txt"}.
-
-Some other option types supported by \module{optparse} are \code{int} and \code{float}.
-Here's an option that expects an integer argument:
-\begin{verbatim}
-parser.add_option("-n", type="int", dest="num")
-\end{verbatim}
-
-Note that this option has no long option string, which is perfectly
-acceptable.  Also, there's no explicit action, since the default is
-\code{store}.
-
-Let's parse another fake command-line.  This time, we'll jam the option
-argument right up against the option: since \code{"-n42"} (one argument) is
-equivalent to \code{"-n 42"} (two arguments), the code
-\begin{verbatim}
-(options, args) = parser.parse_args(["-n42"])
-print options.num
-\end{verbatim}
-
-will print \code{"42"}.
-
-If you don't specify a type, \module{optparse} assumes \code{string}.  Combined with the
-fact that the default action is \code{store}, that means our first example
-can be a lot shorter:
-\begin{verbatim}
-parser.add_option("-f", "--file", dest="filename")
-\end{verbatim}
-
-If you don't supply a destination, \module{optparse} figures out a sensible default
-from the option strings: if the first long option string is
-\code{"-{}-foo-bar"}, then the default destination is \code{foo{\_}bar}.  If there
-are no long option strings, \module{optparse} looks at the first short option
-string: the default destination for \code{"-f"} is \code{f}.
-
-\module{optparse} also includes built-in \code{long} and \code{complex} types.  Adding
-types is covered in section~\ref{optparse-extending-optparse}, Extending \module{optparse}.
-
-
-\subsubsection{Handling boolean (flag) options\label{optparse-handling-boolean-options}}
-
-Flag options{---}set a variable to true or false when a particular option
-is seen{---}are quite common.  \module{optparse} supports them with two separate
-actions, \code{store{\_}true} and \code{store{\_}false}.  For example, you might have a
-\code{verbose} flag that is turned on with \code{"-v"} and off with \code{"-q"}:
-\begin{verbatim}
-parser.add_option("-v", action="store_true", dest="verbose")
-parser.add_option("-q", action="store_false", dest="verbose")
-\end{verbatim}
-
-Here we have two different options with the same destination, which is
-perfectly OK.  (It just means you have to be a bit careful when setting
-default values{---}see below.)
-
-When \module{optparse} encounters \code{"-v"} on the command line, it sets
-\code{options.verbose} to \code{True}; when it encounters \code{"-q"},
-\code{options.verbose} is set to \code{False}.
-
-
-\subsubsection{Other actions\label{optparse-other-actions}}
-
-Some other actions supported by \module{optparse} are:
-\begin{description}
-\item[\code{store{\_}const}]
-store a constant value
-\item[\code{append}]
-append this option's argument to a list
-\item[\code{count}]
-increment a counter by one
-\item[\code{callback}]
-call a specified function
-\end{description}
-
-These are covered in section~\ref{optparse-reference-guide}, Reference Guide and section~\ref{optparse-option-callbacks}, Option Callbacks.
-
-
-\subsubsection{Default values\label{optparse-default-values}}
-
-All of the above examples involve setting some variable (the
-``destination'') when certain command-line options are seen.  What happens
-if those options are never seen?  Since we didn't supply any defaults,
-they are all set to \code{None}.  This is usually fine, but sometimes you
-want more control.  \module{optparse} lets you supply a default value for each
-destination, which is assigned before the command line is parsed.
-
-First, consider the verbose/quiet example.  If we want \module{optparse} to set
-\code{verbose} to \code{True} unless \code{"-q"} is seen, then we can do this:
-\begin{verbatim}
-parser.add_option("-v", action="store_true", dest="verbose", default=True)
-parser.add_option("-q", action="store_false", dest="verbose")
-\end{verbatim}
-
-Since default values apply to the \emph{destination} rather than to any
-particular option, and these two options happen to have the same
-destination, this is exactly equivalent:
-\begin{verbatim}
-parser.add_option("-v", action="store_true", dest="verbose")
-parser.add_option("-q", action="store_false", dest="verbose", default=True)
-\end{verbatim}
-
-Consider this:
-\begin{verbatim}
-parser.add_option("-v", action="store_true", dest="verbose", default=False)
-parser.add_option("-q", action="store_false", dest="verbose", default=True)
-\end{verbatim}
-
-Again, the default value for \code{verbose} will be \code{True}: the last
-default value supplied for any particular destination is the one that
-counts.
-
-A clearer way to specify default values is the \method{set{\_}defaults()}
-method of OptionParser, which you can call at any time before calling
-\method{parse{\_}args()}:
-\begin{verbatim}
-parser.set_defaults(verbose=True)
-parser.add_option(...)
-(options, args) = parser.parse_args()
-\end{verbatim}
-
-As before, the last value specified for a given option destination is
-the one that counts.  For clarity, try to use one method or the other of
-setting default values, not both.
-
-
-\subsubsection{Generating help\label{optparse-generating-help}}
-
-\module{optparse}'s ability to generate help and usage text automatically is useful
-for creating user-friendly command-line interfaces.  All you have to do
-is supply a \member{help} value for each option, and optionally a short usage
-message for your whole program.  Here's an OptionParser populated with
-user-friendly (documented) options:
-\begin{verbatim}
-usage = "usage: %prog [options] arg1 arg2"
-parser = OptionParser(usage=usage)
-parser.add_option("-v", "--verbose",
-                  action="store_true", dest="verbose", default=True,
-                  help="make lots of noise [default]")
-parser.add_option("-q", "--quiet",
-                  action="store_false", dest="verbose", 
-                  help="be vewwy quiet (I'm hunting wabbits)")
-parser.add_option("-f", "--filename",
-                  metavar="FILE", help="write output to FILE"),
-parser.add_option("-m", "--mode",
-                  default="intermediate",
-                  help="interaction mode: novice, intermediate, "
-                       "or expert [default: %default]")
-\end{verbatim}
-
-If \module{optparse} encounters either \code{"-h"} or \code{"-{}-help"} on the command-line,
-or if you just call \method{parser.print{\_}help()}, it prints the following to
-standard output:
-\begin{verbatim}
-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]
-\end{verbatim}
-
-(If the help output is triggered by a help option, \module{optparse} exits after
-printing the help text.)
-
-There's a lot going on here to help \module{optparse} generate the best possible
-help message:
-\begin{itemize}
-\item {} 
-the script defines its own usage message:
-\begin{verbatim}
-usage = "usage: %prog [options] arg1 arg2"
-\end{verbatim}
-
-\module{optparse} expands \code{"{\%}prog"} in the usage string to the name of the current
-program, i.e. \code{os.path.basename(sys.argv{[}0])}.  The expanded string
-is then printed before the detailed option help.
-
-If you don't supply a usage string, \module{optparse} uses a bland but sensible
-default: \code{"usage: {\%}prog {[}options]"}, which is fine if your script
-doesn't take any positional arguments.
-
-\item {} 
-every option defines a help string, and doesn't worry about line-
-wrapping{---}\module{optparse} takes care of wrapping lines and making the
-help output look good.
-
-\item {} 
-options that take a value indicate this fact in their
-automatically-generated help message, e.g. for the ``mode'' option:
-\begin{verbatim}
--m MODE, --mode=MODE
-\end{verbatim}
-
-Here, ``MODE'' is called the meta-variable: it stands for the argument
-that the user is expected to supply to \programopt{-m}/\longprogramopt{mode}.  By default,
-\module{optparse} converts the destination variable name to uppercase and uses
-that for the meta-variable.  Sometimes, that's not what you want{---}for example, the \longprogramopt{filename} option explicitly sets
-\code{metavar="FILE"}, resulting in this automatically-generated option
-description:
-\begin{verbatim}
--f FILE, --filename=FILE
-\end{verbatim}
-
-This is important for more than just saving space, though: the
-manually written help text uses the meta-variable ``FILE'' to clue the
-user in that there's a connection between the semi-formal syntax ``-f
-FILE'' and the informal semantic description ``write output to FILE''.
-This is a simple but effective way to make your help text a lot
-clearer and more useful for end users.
-
-\item {} 
-options that have a default value can include \code{{\%}default} in
-the help string{---}\module{optparse} will replace it with \function{str()} of the
-option's default value.  If an option has no default value (or the
-default value is \code{None}), \code{{\%}default} expands to \code{none}.
-
-\end{itemize}
-
-
-\subsubsection{Printing a version string\label{optparse-printing-version-string}}
-
-Similar to the brief usage string, \module{optparse} can also print a version string
-for your program.  You have to supply the string as the \code{version}
-argument to OptionParser:
-\begin{verbatim}
-parser = OptionParser(usage="%prog [-f] [-q]", version="%prog 1.0")
-\end{verbatim}
-
-\code{"{\%}prog"} is expanded just like it is in \code{usage}.  Apart
-from that, \code{version} can contain anything you like.  When you supply
-it, \module{optparse} automatically adds a \code{"-{}-version"} option to your parser.
-If it encounters this option on the command line, it expands your
-\code{version} string (by replacing \code{"{\%}prog"}), prints it to stdout, and
-exits.
-
-For example, if your script is called \code{/usr/bin/foo}:
-\begin{verbatim}
-$ /usr/bin/foo --version
-foo 1.0
-\end{verbatim}
-
-
-\subsubsection{How \module{optparse} handles errors\label{optparse-how-optparse-handles-errors}}
-
-There are two broad classes of errors that \module{optparse} has to worry about:
-programmer errors and user errors.  Programmer errors are usually
-erroneous calls to \code{parser.add{\_}option()}, e.g. invalid option strings,
-unknown option attributes, missing option attributes, etc.  These are
-dealt with in the usual way: raise an exception (either
-\code{optparse.OptionError} or \code{TypeError}) and let the program crash.
-
-Handling user errors is much more important, since they are guaranteed
-to happen no matter how stable your code is.  \module{optparse} can automatically
-detect some user errors, such as bad option arguments (passing \code{"-n
-4x"} where \programopt{-n} takes an integer argument), missing arguments
-(\code{"-n"} at the end of the command line, where \programopt{-n} takes an argument
-of any type).  Also, you can call \code{parser.error()} to signal an
-application-defined error condition:
-\begin{verbatim}
-(options, args) = parser.parse_args()
-[...]
-if options.a and options.b:
-    parser.error("options -a and -b are mutually exclusive")
-\end{verbatim}
-
-In either case, \module{optparse} handles the error the same way: it prints the
-program's usage message and an error message to standard error and
-exits with error status 2.
-
-Consider the first example above, where the user passes \code{"4x"} to an
-option that takes an integer:
-\begin{verbatim}
-$ /usr/bin/foo -n 4x
-usage: foo [options]
-
-foo: error: option -n: invalid integer value: '4x'
-\end{verbatim}
-
-Or, where the user fails to pass a value at all:
-\begin{verbatim}
-$ /usr/bin/foo -n
-usage: foo [options]
-
-foo: error: -n option requires an argument
-\end{verbatim}
-
-\module{optparse}-generated error messages take care always to mention the option
-involved in the error; be sure to do the same when calling
-\code{parser.error()} from your application code.
-
-If \module{optparse}'s default error-handling behaviour does not suite your needs,
-you'll need to subclass OptionParser and override \code{exit()} and/or
-\method{error()}.
-
-
-\subsubsection{Putting it all together\label{optparse-putting-it-all-together}}
-
-Here's what \module{optparse}-based scripts usually look like:
-\begin{verbatim}
-from optparse import OptionParser
-[...]
-def main():
-    usage = "usage: %prog [options] arg"
-    parser = OptionParser(usage)
-    parser.add_option("-f", "--file", dest="filename",
-                      help="read data from FILENAME")
-    parser.add_option("-v", "--verbose",
-                      action="store_true", dest="verbose")
-    parser.add_option("-q", "--quiet",
-                      action="store_false", dest="verbose")
-    [...]
-    (options, args) = parser.parse_args()
-    if len(args) != 1:
-        parser.error("incorrect number of arguments")
-    if options.verbose:
-        print "reading %s..." % options.filename
-    [...]
-
-if __name__ == "__main__":
-    main()
-\end{verbatim}
-% $Id: tutorial.txt 515 2006-06-10 15:37:45Z gward $ 
-
-
-\subsection{Reference Guide\label{optparse-reference-guide}}
-
-
-\subsubsection{Creating the parser\label{optparse-creating-parser}}
-
-The first step in using \module{optparse} is to create an OptionParser instance:
-\begin{verbatim}
-parser = OptionParser(...)
-\end{verbatim}
-
-The OptionParser constructor has no required arguments, but a number of
-optional keyword arguments.  You should always pass them as keyword
-arguments, i.e. do not rely on the order in which the arguments are
-declared.
-\begin{quote}
-\begin{description}
-\item[\code{usage} (default: \code{"{\%}prog {[}options]"})]
-The usage summary to print when your program is run incorrectly or
-with a help option.  When \module{optparse} prints the usage string, it expands
-\code{{\%}prog} to \code{os.path.basename(sys.argv{[}0])} (or to \code{prog} if
-you passed that keyword argument).  To suppress a usage message,
-pass the special value \code{optparse.SUPPRESS{\_}USAGE}.
-\item[\code{option{\_}list} (default: \code{{[}]})]
-A list of Option objects to populate the parser with.  The options
-in \code{option{\_}list} are added after any options in
-\code{standard{\_}option{\_}list} (a class attribute that may be set by
-OptionParser subclasses), but before any version or help options.
-Deprecated; use \method{add{\_}option()} after creating the parser instead.
-\item[\code{option{\_}class} (default: optparse.Option)]
-Class to use when adding options to the parser in \method{add{\_}option()}.
-\item[\code{version} (default: \code{None})]
-A version string to print when the user supplies a version option.
-If you supply a true value for \code{version}, \module{optparse} automatically adds
-a version option with the single option string \code{"-{}-version"}.  The
-substring \code{"{\%}prog"} is expanded the same as for \code{usage}.
-\item[\code{conflict{\_}handler} (default: \code{"error"})]
-Specifies what to do when options with conflicting option strings
-are added to the parser; see section~\ref{optparse-conflicts-between-options}, Conflicts between options.
-\item[\code{description} (default: \code{None})]
-A paragraph of text giving a brief overview of your program.  \module{optparse}
-reformats this paragraph to fit the current terminal width and
-prints it when the user requests help (after \code{usage}, but before
-the list of options).
-\item[\code{formatter} (default: a new IndentedHelpFormatter)]
-An instance of optparse.HelpFormatter that will be used for
-printing help text.  \module{optparse} provides two concrete classes for this
-purpose: IndentedHelpFormatter and TitledHelpFormatter.
-\item[\code{add{\_}help{\_}option} (default: \code{True})]
-If true, \module{optparse} will add a help option (with option strings \code{"-h"}
-and \code{"-{}-help"}) to the parser.
-\item[\code{prog}]
-The string to use when expanding \code{"{\%}prog"} in \code{usage} and
-\code{version} instead of \code{os.path.basename(sys.argv{[}0])}.
-\end{description}
-\end{quote}
-
-
-\subsubsection{Populating the parser\label{optparse-populating-parser}}
-
-There are several ways to populate the parser with options.  The
-preferred way is by using \code{OptionParser.add{\_}option()}, as shown in
-section~\ref{optparse-tutorial}, the tutorial.  \method{add{\_}option()} can be called in one of two
-ways:
-\begin{itemize}
-\item {} 
-pass it an Option instance (as returned by \function{make{\_}option()})
-
-\item {} 
-pass it any combination of positional and keyword arguments that are
-acceptable to \function{make{\_}option()} (i.e., to the Option constructor),
-and it will create the Option instance for you
-
-\end{itemize}
-
-The other alternative is to pass a list of pre-constructed Option
-instances to the OptionParser constructor, as in:
-\begin{verbatim}
-option_list = [
-    make_option("-f", "--filename",
-                action="store", type="string", dest="filename"),
-    make_option("-q", "--quiet",
-                action="store_false", dest="verbose"),
-    ]
-parser = OptionParser(option_list=option_list)
-\end{verbatim}
-
-(\function{make{\_}option()} is a factory function for creating Option instances;
-currently it is an alias for the Option constructor.  A future version
-of \module{optparse} may split Option into several classes, and \function{make{\_}option()}
-will pick the right class to instantiate.  Do not instantiate Option
-directly.)
-
-
-\subsubsection{Defining options\label{optparse-defining-options}}
-
-Each Option instance represents a set of synonymous command-line option
-strings, e.g. \programopt{-f} and \longprogramopt{file}.  You can
-specify any number of short or long option strings, but you must specify
-at least one overall option string.
-
-The canonical way to create an Option instance is with the
-\method{add{\_}option()} method of \class{OptionParser}:
-\begin{verbatim}
-parser.add_option(opt_str[, ...], attr=value, ...)
-\end{verbatim}
-
-To define an option with only a short option string:
-\begin{verbatim}
-parser.add_option("-f", attr=value, ...)
-\end{verbatim}
-
-And to define an option with only a long option string:
-\begin{verbatim}
-parser.add_option("--foo", attr=value, ...)
-\end{verbatim}
-
-The keyword arguments define attributes of the new Option object.  The
-most important option attribute is \member{action}, and it largely determines
-which other attributes are relevant or required.  If you pass irrelevant
-option attributes, or fail to pass required ones, \module{optparse} raises an
-OptionError exception explaining your mistake.
-
-An options's \emph{action} determines what \module{optparse} does when it encounters this
-option on the command-line.  The standard option actions hard-coded into
-\module{optparse} are:
-\begin{description}
-\item[\code{store}]
-store this option's argument (default)
-\item[\code{store{\_}const}]
-store a constant value
-\item[\code{store{\_}true}]
-store a true value
-\item[\code{store{\_}false}]
-store a false value
-\item[\code{append}]
-append this option's argument to a list
-\item[\code{append{\_}const}]
-append a constant value to a list
-\item[\code{count}]
-increment a counter by one
-\item[\code{callback}]
-call a specified function
-\item[\member{help}]
-print a usage message including all options and the
-documentation for them
-\end{description}
-
-(If you don't supply an action, the default is \code{store}.  For this
-action, you may also supply \member{type} and \member{dest} option attributes; see
-below.)
-
-As you can see, most actions involve storing or updating a value
-somewhere.  \module{optparse} always creates a special object for this,
-conventionally called \code{options} (it happens to be an instance of
-\code{optparse.Values}).  Option arguments (and various other values) are
-stored as attributes of this object, according to the \member{dest}
-(destination) option attribute.
-
-For example, when you call
-\begin{verbatim}
-parser.parse_args()
-\end{verbatim}
-
-one of the first things \module{optparse} does is create the \code{options} object:
-\begin{verbatim}
-options = Values()
-\end{verbatim}
-
-If one of the options in this parser is defined with
-\begin{verbatim}
-parser.add_option("-f", "--file", action="store", type="string", dest="filename")
-\end{verbatim}
-
-and the command-line being parsed includes any of the following:
-\begin{verbatim}
--ffoo
--f foo
---file=foo
---file foo
-\end{verbatim}
-
-then \module{optparse}, on seeing this option, will do the equivalent of
-\begin{verbatim}
-options.filename = "foo"
-\end{verbatim}
-
-The \member{type} and \member{dest} option attributes are almost as important as
-\member{action}, but \member{action} is the only one that makes sense for \emph{all}
-options.
-
-
-\subsubsection{Standard option actions\label{optparse-standard-option-actions}}
-
-The various option actions all have slightly different requirements and
-effects.  Most actions have several relevant option attributes which you
-may specify to guide \module{optparse}'s behaviour; a few have required attributes,
-which you must specify for any option using that action.
-\begin{itemize}
-\item {} 
-\code{store} {[}relevant: \member{type}, \member{dest}, \code{nargs}, \code{choices}]
-
-The option must be followed by an argument, which is
-converted to a value according to \member{type} and stored in
-\member{dest}.  If \code{nargs} {\textgreater} 1, multiple arguments will be consumed
-from the command line; all will be converted according to
-\member{type} and stored to \member{dest} as a tuple.  See the ``Option
-types'' section below.
-
-If \code{choices} is supplied (a list or tuple of strings), the type
-defaults to \code{choice}.
-
-If \member{type} is not supplied, it defaults to \code{string}.
-
-If \member{dest} is not supplied, \module{optparse} derives a destination from the
-first long option string (e.g., \code{"-{}-foo-bar"} implies \code{foo{\_}bar}).
-If there are no long option strings, \module{optparse} derives a destination from
-the first short option string (e.g., \code{"-f"} implies \code{f}).
-
-Example:
-\begin{verbatim}
-parser.add_option("-f")
-parser.add_option("-p", type="float", nargs=3, dest="point")
-\end{verbatim}
-
-As it parses the command line
-\begin{verbatim}
--f foo.txt -p 1 -3.5 4 -fbar.txt
-\end{verbatim}
-
-\module{optparse} will set
-\begin{verbatim}
-options.f = "foo.txt"
-options.point = (1.0, -3.5, 4.0)
-options.f = "bar.txt"
-\end{verbatim}
-
-\item {} 
-\code{store{\_}const} {[}required: \code{const}; relevant: \member{dest}]
-
-The value \code{const} is stored in \member{dest}.
-
-Example:
-\begin{verbatim}
-parser.add_option("-q", "--quiet",
-                  action="store_const", const=0, dest="verbose")
-parser.add_option("-v", "--verbose",
-                  action="store_const", const=1, dest="verbose")
-parser.add_option("--noisy",
-                  action="store_const", const=2, dest="verbose")
-\end{verbatim}
-
-If \code{"-{}-noisy"} is seen, \module{optparse} will set
-\begin{verbatim}
-options.verbose = 2
-\end{verbatim}
-
-\item {} 
-\code{store{\_}true} {[}relevant: \member{dest}]
-
-A special case of \code{store{\_}const} that stores a true value
-to \member{dest}.
-
-\item {} 
-\code{store{\_}false} {[}relevant: \member{dest}]
-
-Like \code{store{\_}true}, but stores a false value.
-
-Example:
-\begin{verbatim}
-parser.add_option("--clobber", action="store_true", dest="clobber")
-parser.add_option("--no-clobber", action="store_false", dest="clobber")
-\end{verbatim}
-
-\item {} 
-\code{append} {[}relevant: \member{type}, \member{dest}, \code{nargs}, \code{choices}]
-
-The option must be followed by an argument, which is appended to the
-list in \member{dest}.  If no default value for \member{dest} is supplied, an
-empty list is automatically created when \module{optparse} first encounters this
-option on the command-line.  If \code{nargs} {\textgreater} 1, multiple arguments are
-consumed, and a tuple of length \code{nargs} is appended to \member{dest}.
-
-The defaults for \member{type} and \member{dest} are the same as for the
-\code{store} action.
-
-Example:
-\begin{verbatim}
-parser.add_option("-t", "--tracks", action="append", type="int")
-\end{verbatim}
-
-If \code{"-t3"} is seen on the command-line, \module{optparse} does the equivalent of:
-\begin{verbatim}
-options.tracks = []
-options.tracks.append(int("3"))
-\end{verbatim}
-
-If, a little later on, \code{"-{}-tracks=4"} is seen, it does:
-\begin{verbatim}
-options.tracks.append(int("4"))
-\end{verbatim}
-
-\item {} 
-\code{append{\_}const} {[}required: \code{const}; relevant: \member{dest}]
-
-Like \code{store{\_}const}, but the value \code{const} is appended to \member{dest};
-as with \code{append}, \member{dest} defaults to \code{None}, and an an empty list is
-automatically created the first time the option is encountered.
-
-\item {} 
-\code{count} {[}relevant: \member{dest}]
-
-Increment the integer stored at \member{dest}.  If no default value is
-supplied, \member{dest} is set to zero before being incremented the first
-time.
-
-Example:
-\begin{verbatim}
-parser.add_option("-v", action="count", dest="verbosity")
-\end{verbatim}
-
-The first time \code{"-v"} is seen on the command line, \module{optparse} does the
-equivalent of:
-\begin{verbatim}
-options.verbosity = 0
-options.verbosity += 1
-\end{verbatim}
-
-Every subsequent occurrence of \code{"-v"} results in
-\begin{verbatim}
-options.verbosity += 1
-\end{verbatim}
-
-\item {} 
-\code{callback} {[}required: \code{callback};
-relevant: \member{type}, \code{nargs}, \code{callback{\_}args}, \code{callback{\_}kwargs}]
-
-Call the function specified by \code{callback}, which is called as
-\begin{verbatim}
-func(option, opt_str, value, parser, *args, **kwargs)
-\end{verbatim}
-
-See section~\ref{optparse-option-callbacks}, Option Callbacks for more detail.
-
-\item {} 
-\member{help}
-
-Prints a complete help message for all the options in the
-current option parser.  The help message is constructed from
-the \code{usage} string passed to OptionParser's constructor and
-the \member{help} string passed to every option.
-
-If no \member{help} string is supplied for an option, it will still be
-listed in the help message.  To omit an option entirely, use
-the special value \code{optparse.SUPPRESS{\_}HELP}.
-
-\module{optparse} automatically adds a \member{help} option to all OptionParsers, so
-you do not normally need to create one.
-
-Example:
-\begin{verbatim}
-from optparse import OptionParser, SUPPRESS_HELP
-
-parser = OptionParser()
-parser.add_option("-h", "--help", action="help"),
-parser.add_option("-v", action="store_true", dest="verbose",
-                  help="Be moderately verbose")
-parser.add_option("--file", dest="filename",
-                  help="Input file to read data from"),
-parser.add_option("--secret", help=SUPPRESS_HELP)
-\end{verbatim}
-
-If \module{optparse} sees either \code{"-h"} or \code{"-{}-help"} on the command line, it
-will print something like the following help message to stdout
-(assuming \code{sys.argv{[}0]} is \code{"foo.py"}):
-\begin{verbatim}
-usage: foo.py [options]
-
-options:
-  -h, --help        Show this help message and exit
-  -v                Be moderately verbose
-  --file=FILENAME   Input file to read data from
-\end{verbatim}
-
-After printing the help message, \module{optparse} terminates your process
-with \code{sys.exit(0)}.
-
-\item {} 
-\code{version}
-
-Prints the version number supplied to the OptionParser to stdout and
-exits.  The version number is actually formatted and printed by the
-\code{print{\_}version()} method of OptionParser.  Generally only relevant
-if the \code{version} argument is supplied to the OptionParser
-constructor.  As with \member{help} options, you will rarely create
-\code{version} options, since \module{optparse} automatically adds them when needed.
-
-\end{itemize}
-
-
-\subsubsection{Option attributes\label{optparse-option-attributes}}
-
-The following option attributes may be passed as keyword arguments
-to \code{parser.add{\_}option()}.  If you pass an option attribute
-that is not relevant to a particular option, or fail to pass a required
-option attribute, \module{optparse} raises OptionError.
-\begin{itemize}
-\item {} 
-\member{action} (default: \code{"store"})
-
-Determines \module{optparse}'s behaviour when this option is seen on the command
-line; the available options are documented above.
-
-\item {} 
-\member{type} (default: \code{"string"})
-
-The argument type expected by this option (e.g., \code{"string"} or
-\code{"int"}); the available option types are documented below.
-
-\item {} 
-\member{dest} (default: derived from option strings)
-
-If the option's action implies writing or modifying a value somewhere,
-this tells \module{optparse} where to write it: \member{dest} names an attribute of the
-\code{options} object that \module{optparse} builds as it parses the command line.
-
-\item {} 
-\code{default} (deprecated)
-
-The value to use for this option's destination if the option is not
-seen on the command line.  Deprecated; use \code{parser.set{\_}defaults()}
-instead.
-
-\item {} 
-\code{nargs} (default: 1)
-
-How many arguments of type \member{type} should be consumed when this
-option is seen.  If {\textgreater} 1, \module{optparse} will store a tuple of values to
-\member{dest}.
-
-\item {} 
-\code{const}
-
-For actions that store a constant value, the constant value to store.
-
-\item {} 
-\code{choices}
-
-For options of type \code{"choice"}, the list of strings the user
-may choose from.
-
-\item {} 
-\code{callback}
-
-For options with action \code{"callback"}, the callable to call when this
-option is seen.  See section~\ref{optparse-option-callbacks}, Option Callbacks for detail on the arguments
-passed to \code{callable}.
-
-\item {} 
-\code{callback{\_}args}, \code{callback{\_}kwargs}
-
-Additional positional and keyword arguments to pass to \code{callback}
-after the four standard callback arguments.
-
-\item {} 
-\member{help}
-
-Help text to print for this option when listing all available options
-after the user supplies a \member{help} option (such as \code{"-{}-help"}).
-If no help text is supplied, the option will be listed without help
-text.  To hide this option, use the special value \code{SUPPRESS{\_}HELP}.
-
-\item {} 
-\code{metavar} (default: derived from option strings)
-
-Stand-in for the option argument(s) to use when printing help text.
-See section~\ref{optparse-tutorial}, the tutorial for an example.
-
-\end{itemize}
-
-
-\subsubsection{Standard option types\label{optparse-standard-option-types}}
-
-\module{optparse} has six built-in option types: \code{string}, \code{int}, \code{long},
-\code{choice}, \code{float} and \code{complex}.  If you need to add new option
-types, see section~\ref{optparse-extending-optparse}, Extending \module{optparse}.
-
-Arguments to string options are not checked or converted in any way: the
-text on the command line is stored in the destination (or passed to the
-callback) as-is.
-
-Integer arguments (type \code{int} or \code{long}) are parsed as follows:
-\begin{quote}
-\begin{itemize}
-\item {} 
-if the number starts with \code{0x}, it is parsed as a hexadecimal number
-
-\item {} 
-if the number starts with \code{0}, it is parsed as an octal number
-
-\item {} 
-if the number starts with \code{0b}, is is parsed as a binary number
-
-\item {} 
-otherwise, the number is parsed as a decimal number
-
-\end{itemize}
-\end{quote}
-
-The conversion is done by calling either \code{int()} or \code{long()} with
-the appropriate base (2, 8, 10, or 16).  If this fails, so will \module{optparse},
-although with a more useful error message.
-
-\code{float} and \code{complex} option arguments are converted directly with
-\code{float()} and \code{complex()}, with similar error-handling.
-
-\code{choice} options are a subtype of \code{string} options.  The \code{choices}
-option attribute (a sequence of strings) defines the set of allowed
-option arguments.  \code{optparse.check{\_}choice()} compares
-user-supplied option arguments against this master list and raises
-OptionValueError if an invalid string is given.
-
-
-\subsubsection{Parsing arguments\label{optparse-parsing-arguments}}
-
-The whole point of creating and populating an OptionParser is to call
-its \method{parse{\_}args()} method:
-\begin{verbatim}
-(options, args) = parser.parse_args(args=None, values=None)
-\end{verbatim}
-
-where the input parameters are
-\begin{description}
-\item[\code{args}]
-the list of arguments to process (default: \code{sys.argv{[}1:]})
-\item[\code{values}]
-object to store option arguments in (default: a new instance of
-optparse.Values)
-\end{description}
-
-and the return values are
-\begin{description}
-\item[\code{options}]
-the same object that was passed in as \code{options}, or the
-optparse.Values instance created by \module{optparse}
-\item[\code{args}]
-the leftover positional arguments after all options have been
-processed
-\end{description}
-
-The most common usage is to supply neither keyword argument.  If you
-supply \code{options}, it will be modified with repeated \code{setattr()}
-calls (roughly one for every option argument stored to an option
-destination) and returned by \method{parse{\_}args()}.
-
-If \method{parse{\_}args()} encounters any errors in the argument list, it calls
-the OptionParser's \method{error()} method with an appropriate end-user error
-message.  This ultimately terminates your process with an exit status of
-2 (the traditional \UNIX{} exit status for command-line errors).
-
-
-\subsubsection{Querying and manipulating your option parser\label{optparse-querying-manipulating-option-parser}}
-
-Sometimes, it's useful to poke around your option parser and see what's
-there.  OptionParser provides a couple of methods to help you out:
-\begin{description}
-\item[\code{has{\_}option(opt{\_}str)}]
-Return true if the OptionParser has an option with 
-option string \code{opt{\_}str} (e.g., \code{"-q"} or \code{"-{}-verbose"}).
-\item[\code{get{\_}option(opt{\_}str)}]
-Returns the Option instance with the option string \code{opt{\_}str}, or
-\code{None} if no options have that option string.
-\item[\code{remove{\_}option(opt{\_}str)}]
-If the OptionParser has an option corresponding to \code{opt{\_}str},
-that option is removed.  If that option provided any other
-option strings, all of those option strings become invalid.
-If \code{opt{\_}str} does not occur in any option belonging to this
-OptionParser, raises ValueError.
-\end{description}
-
-
-\subsubsection{Conflicts between options\label{optparse-conflicts-between-options}}
-
-If you're not careful, it's easy to define options with conflicting
-option strings:
-\begin{verbatim}
-parser.add_option("-n", "--dry-run", ...)
-[...]
-parser.add_option("-n", "--noisy", ...)
-\end{verbatim}
-
-(This is particularly true if you've defined your own OptionParser
-subclass with some standard options.)
-
-Every time you add an option, \module{optparse} checks for conflicts with existing
-options.  If it finds any, it invokes the current conflict-handling
-mechanism.  You can set the conflict-handling mechanism either in the
-constructor:
-\begin{verbatim}
-parser = OptionParser(..., conflict_handler=handler)
-\end{verbatim}
-
-or with a separate call:
-\begin{verbatim}
-parser.set_conflict_handler(handler)
-\end{verbatim}
-
-The available conflict handlers are:
-\begin{quote}
-\begin{description}
-\item[\code{error} (default)]
-assume option conflicts are a programming error and raise 
-OptionConflictError
-\item[\code{resolve}]
-resolve option conflicts intelligently (see below)
-\end{description}
-\end{quote}
-
-As an example, let's define an OptionParser that resolves conflicts
-intelligently and add conflicting options to it:
-\begin{verbatim}
-parser = OptionParser(conflict_handler="resolve")
-parser.add_option("-n", "--dry-run", ..., help="do no harm")
-parser.add_option("-n", "--noisy", ..., help="be noisy")
-\end{verbatim}
-
-At this point, \module{optparse} detects that a previously-added option is already
-using the \code{"-n"} option string.  Since \code{conflict{\_}handler} is
-\code{"resolve"}, it resolves the situation by removing \code{"-n"} from the
-earlier option's list of option strings.  Now \code{"-{}-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:
-\begin{verbatim}
-options:
-  --dry-run     do no harm
-  [...]
-  -n, --noisy   be noisy
-\end{verbatim}
-
-It's possible to whittle away the option strings for a previously-added
-option until there are none left, and the user has no way of invoking
-that option from the command-line.  In that case, \module{optparse} removes that
-option completely, so it doesn't show up in help text or anywhere else.
-Carrying on with our existing OptionParser:
-\begin{verbatim}
-parser.add_option("--dry-run", ..., help="new dry-run option")
-\end{verbatim}
-
-At this point, the original \programopt{-n/-{}-dry-run} option is no longer
-accessible, so \module{optparse} removes it, leaving this help text:
-\begin{verbatim}
-options:
-  [...]
-  -n, --noisy   be noisy
-  --dry-run     new dry-run option
-\end{verbatim}
-
-
-\subsubsection{Cleanup\label{optparse-cleanup}}
-
-OptionParser instances have several cyclic references.  This should not
-be a problem for Python's garbage collector, but you may wish to break
-the cyclic references explicitly by calling \code{destroy()} on your
-OptionParser once you are done with it.  This is particularly useful in
-long-running applications where large object graphs are reachable from
-your OptionParser.
-
-
-\subsubsection{Other methods\label{optparse-other-methods}}
-
-OptionParser supports several other public methods:
-\begin{itemize}
-\item {} 
-\code{set{\_}usage(usage)}
-
-Set the usage string according to the rules described above for the
-\code{usage} constructor keyword argument.  Passing \code{None} sets the
-default usage string; use \code{SUPPRESS{\_}USAGE} to suppress a usage
-message.
-
-\item {} 
-\code{enable{\_}interspersed{\_}args()}, \code{disable{\_}interspersed{\_}args()}
-
-Enable/disable positional arguments interspersed with options, similar
-to GNU getopt (enabled by default).  For example, if \code{"-a"} and
-\code{"-b"} are both simple options that take no arguments, \module{optparse}
-normally accepts this syntax:
-\begin{verbatim}
-prog -a arg1 -b arg2
-\end{verbatim}
-
-and treats it as equivalent to
-\begin{verbatim}
-prog -a -b arg1 arg2
-\end{verbatim}
-
-To disable this feature, call \code{disable{\_}interspersed{\_}args()}.  This
-restores traditional \UNIX{} syntax, where option parsing stops with the
-first non-option argument.
-
-\item {} 
-\code{set{\_}defaults(dest=value, ...)}
-
-Set default values for several option destinations at once.  Using
-\method{set{\_}defaults()} is the preferred way to set default values for
-options, since multiple options can share the same destination.  For
-example, if several ``mode'' options all set the same destination, any
-one of them can set the default, and the last one wins:
-\begin{verbatim}
-parser.add_option("--advanced", action="store_const",
-                  dest="mode", const="advanced",
-                  default="novice")    # overridden below
-parser.add_option("--novice", action="store_const",
-                  dest="mode", const="novice",
-                  default="advanced")  # overrides above setting
-\end{verbatim}
-
-To avoid this confusion, use \method{set{\_}defaults()}:
-\begin{verbatim}
-parser.set_defaults(mode="advanced")
-parser.add_option("--advanced", action="store_const",
-                  dest="mode", const="advanced")
-parser.add_option("--novice", action="store_const",
-                  dest="mode", const="novice")
-\end{verbatim}
-
-\end{itemize}
-% $Id: reference.txt 519 2006-06-11 14:39:11Z gward $ 
-
-
-\subsection{Option Callbacks\label{optparse-option-callbacks}}
-
-When \module{optparse}'s built-in actions and types aren't quite enough for your
-needs, you have two choices: extend \module{optparse} or define a callback option.
-Extending \module{optparse} is more general, but overkill for a lot of simple
-cases.  Quite often a simple callback is all you need.
-
-There are two steps to defining a callback option:
-\begin{itemize}
-\item {} 
-define the option itself using the \code{callback} action
-
-\item {} 
-write the callback; this is a function (or method) that
-takes at least four arguments, as described below
-
-\end{itemize}
-
-
-\subsubsection{Defining a callback option\label{optparse-defining-callback-option}}
-
-As always, the easiest way to define a callback option is by using the
-\code{parser.add{\_}option()} method.  Apart from \member{action}, the only option
-attribute you must specify is \code{callback}, the function to call:
-\begin{verbatim}
-parser.add_option("-c", action="callback", callback=my_callback)
-\end{verbatim}
-
-\code{callback} is a function (or other callable object), so you must have
-already defined \code{my{\_}callback()} when you create this callback option.
-In this simple case, \module{optparse} doesn't even know if \programopt{-c} takes any
-arguments, which usually means that the option takes no arguments{---}the
-mere presence of \programopt{-c} on the command-line is all it needs to know.  In
-some circumstances, though, you might want your callback to consume an
-arbitrary number of command-line arguments.  This is where writing
-callbacks gets tricky; it's covered later in this section.
-
-\module{optparse} always passes four particular arguments to your callback, and it
-will only pass additional arguments if you specify them via
-\code{callback{\_}args} and \code{callback{\_}kwargs}.  Thus, the minimal callback
-function signature is:
-\begin{verbatim}
-def my_callback(option, opt, value, parser):
-\end{verbatim}
-
-The four arguments to a callback are described below.
-
-There are several other option attributes that you can supply when you
-define a callback option:
-\begin{description}
-\item[\member{type}]
-has its usual meaning: as with the \code{store} or \code{append} actions,
-it instructs \module{optparse} to consume one argument and convert it to
-\member{type}.  Rather than storing the converted value(s) anywhere,
-though, \module{optparse} passes it to your callback function.
-\item[\code{nargs}]
-also has its usual meaning: if it is supplied and {\textgreater} 1, \module{optparse} will
-consume \code{nargs} arguments, each of which must be convertible to
-\member{type}.  It then passes a tuple of converted values to your
-callback.
-\item[\code{callback{\_}args}]
-a tuple of extra positional arguments to pass to the callback
-\item[\code{callback{\_}kwargs}]
-a dictionary of extra keyword arguments to pass to the callback
-\end{description}
-
-
-\subsubsection{How callbacks are called\label{optparse-how-callbacks-called}}
-
-All callbacks are called as follows:
-\begin{verbatim}
-func(option, opt_str, value, parser, *args, **kwargs)
-\end{verbatim}
-
-where
-\begin{description}
-\item[\code{option}]
-is the Option instance that's calling the callback
-\item[\code{opt{\_}str}]
-is the option string seen on the command-line that's triggering the
-callback.  (If an abbreviated long option was used, \code{opt{\_}str} will
-be the full, canonical option string{---}e.g. if the user puts
-\code{"-{}-foo"} on the command-line as an abbreviation for
-\code{"-{}-foobar"}, then \code{opt{\_}str} will be \code{"-{}-foobar"}.)
-\item[\code{value}]
-is the argument to this option seen on the command-line.  \module{optparse} will
-only expect an argument if \member{type} is set; the type of \code{value}
-will be the type implied by the option's type.  If \member{type} for this
-option is \code{None} (no argument expected), then \code{value} will be
-\code{None}.  If \code{nargs} {\textgreater} 1, \code{value} will be a tuple of values of
-the appropriate type.
-\item[\code{parser}]
-is the OptionParser instance driving the whole thing, mainly
-useful because you can access some other interesting data through
-its instance attributes:
-\begin{description}
-\item[\code{parser.largs}]
-the current list of leftover arguments, ie. arguments that have
-been consumed but are neither options nor option arguments.
-Feel free to modify \code{parser.largs}, e.g. by adding more
-arguments to it.  (This list will become \code{args}, the second
-return value of \method{parse{\_}args()}.)
-\item[\code{parser.rargs}]
-the current list of remaining arguments, ie. with \code{opt{\_}str} and
-\code{value} (if applicable) removed, and only the arguments
-following them still there.  Feel free to modify
-\code{parser.rargs}, e.g. by consuming more arguments.
-\item[\code{parser.values}]
-the object where option values are by default stored (an
-instance of optparse.OptionValues).  This lets callbacks use the
-same mechanism as the rest of \module{optparse} for storing option values;
-you don't need to mess around with globals or closures.  You can
-also access or modify the value(s) of any options already
-encountered on the command-line.
-\end{description}
-\item[\code{args}]
-is a tuple of arbitrary positional arguments supplied via the
-\code{callback{\_}args} option attribute.
-\item[\code{kwargs}]
-is a dictionary of arbitrary keyword arguments supplied via
-\code{callback{\_}kwargs}.
-\end{description}
-
-
-\subsubsection{Raising errors in a callback\label{optparse-raising-errors-in-callback}}
-
-The callback function should raise OptionValueError if there are any
-problems with the option or its argument(s).  \module{optparse} catches this and
-terminates the program, printing the error message you supply to
-stderr.  Your message should be clear, concise, accurate, and mention
-the option at fault.  Otherwise, the user will have a hard time
-figuring out what he did wrong.
-
-
-\subsubsection{Callback example 1: trivial callback\label{optparse-callback-example-1}}
-
-Here's an example of a callback option that takes no arguments, and
-simply records that the option was seen:
-\begin{verbatim}
-def record_foo_seen(option, opt_str, value, parser):
-    parser.saw_foo = True
-
-parser.add_option("--foo", action="callback", callback=record_foo_seen)
-\end{verbatim}
-
-Of course, you could do that with the \code{store{\_}true} action.
-
-
-\subsubsection{Callback example 2: check option order\label{optparse-callback-example-2}}
-
-Here's a slightly more interesting example: record the fact that
-\code{"-a"} is seen, but blow up if it comes after \code{"-b"} in the
-command-line.
-\begin{verbatim}
-def check_order(option, opt_str, value, parser):
-    if parser.values.b:
-        raise OptionValueError("can't use -a after -b")
-    parser.values.a = 1
-[...]
-parser.add_option("-a", action="callback", callback=check_order)
-parser.add_option("-b", action="store_true", dest="b")
-\end{verbatim}
-
-
-\subsubsection{Callback example 3: check option order (generalized)\label{optparse-callback-example-3}}
-
-If you want to re-use this callback for several similar options (set a
-flag, but blow up if \code{"-b"} has already been seen), it needs a bit of
-work: the error message and the flag that it sets must be
-generalized.
-\begin{verbatim}
-def check_order(option, opt_str, value, parser):
-    if parser.values.b:
-        raise OptionValueError("can't use %s after -b" % opt_str)
-    setattr(parser.values, option.dest, 1)
-[...]
-parser.add_option("-a", action="callback", callback=check_order, dest='a')
-parser.add_option("-b", action="store_true", dest="b")
-parser.add_option("-c", action="callback", callback=check_order, dest='c')
-\end{verbatim}
-
-
-\subsubsection{Callback example 4: check arbitrary condition\label{optparse-callback-example-4}}
-
-Of course, you could put any condition in there{---}you're not limited
-to checking the values of already-defined options.  For example, if
-you have options that should not be called when the moon is full, all
-you have to do is this:
-\begin{verbatim}
-def check_moon(option, opt_str, value, parser):
-    if is_moon_full():
-        raise OptionValueError("%s option invalid when moon is full"
-                               % opt_str)
-    setattr(parser.values, option.dest, 1)
-[...]
-parser.add_option("--foo",
-                  action="callback", callback=check_moon, dest="foo")
-\end{verbatim}
-
-(The definition of \code{is{\_}moon{\_}full()} is left as an exercise for the
-reader.)
-
-
-\subsubsection{Callback example 5: fixed arguments\label{optparse-callback-example-5}}
-
-Things get slightly more interesting when you define callback options
-that take a fixed number of arguments.  Specifying that a callback
-option takes arguments is similar to defining a \code{store} or \code{append}
-option: if you define \member{type}, then the option takes one argument that
-must be convertible to that type; if you further define \code{nargs}, then
-the option takes \code{nargs} arguments.
-
-Here's an example that just emulates the standard \code{store} action:
-\begin{verbatim}
-def store_value(option, opt_str, value, parser):
-    setattr(parser.values, option.dest, value)
-[...]
-parser.add_option("--foo",
-                  action="callback", callback=store_value,
-                  type="int", nargs=3, dest="foo")
-\end{verbatim}
-
-Note that \module{optparse} takes care of consuming 3 arguments and converting them
-to integers for you; all you have to do is store them.  (Or whatever;
-obviously you don't need a callback for this example.)
-
-
-\subsubsection{Callback example 6: variable arguments\label{optparse-callback-example-6}}
-
-Things get hairy when you want an option to take a variable number of
-arguments.  For this case, you must write a callback, as \module{optparse} doesn't
-provide any built-in capabilities for it.  And you have to deal with
-certain intricacies of conventional \UNIX{} command-line parsing that \module{optparse}
-normally handles for you.  In particular, callbacks should implement
-the conventional rules for bare \code{"-{}-"} and \code{"-"} arguments:
-\begin{itemize}
-\item {} 
-either \code{"-{}-"} or \code{"-"} can be option arguments
-
-\item {} 
-bare \code{"-{}-"} (if not the argument to some option): halt command-line
-processing and discard the \code{"-{}-"}
-
-\item {} 
-bare \code{"-"} (if not the argument to some option): halt command-line
-processing but keep the \code{"-"} (append it to \code{parser.largs})
-
-\end{itemize}
-
-If you want an option that takes a variable number of arguments, there
-are several subtle, tricky issues to worry about.  The exact
-implementation you choose will be based on which trade-offs you're
-willing to make for your application (which is why \module{optparse} doesn't support
-this sort of thing directly).
-
-Nevertheless, here's a stab at a callback for an option with variable
-arguments:
-\begin{verbatim}
-def vararg_callback(option, opt_str, value, parser):
-    assert value is None
-    done = 0
-    value = []
-    rargs = parser.rargs
-    while rargs:
-        arg = rargs[0]
-
-        # Stop if we hit an arg like "--foo", "-a", "-fx", "--file=f",
-        # etc.  Note that this also stops on "-3" or "-3.0", so if
-        # your option takes numeric values, you will need to handle
-        # this.
-        if ((arg[:2] == "--" and len(arg) > 2) or
-            (arg[:1] == "-" and len(arg) > 1 and arg[1] != "-")):
-            break
-        else:
-            value.append(arg)
-            del rargs[0]
-
-     setattr(parser.values, option.dest, value)
-
-[...]
-parser.add_option("-c", "--callback",
-                  action="callback", callback=varargs)
-\end{verbatim}
-
-The main weakness with this particular implementation is that negative
-numbers in the arguments following \code{"-c"} will be interpreted as
-further options (probably causing an error), rather than as arguments to
-\code{"-c"}.  Fixing this is left as an exercise for the reader.
-% $Id: callbacks.txt 415 2004-09-30 02:26:17Z greg $ 
-
-
-\subsection{Extending \module{optparse}\label{optparse-extending-optparse}}
-
-Since the two major controlling factors in how \module{optparse} interprets
-command-line options are the action and type of each option, the most
-likely direction of extension is to add new actions and new types.
-
-
-\subsubsection{Adding new types\label{optparse-adding-new-types}}
-
-To add new types, you need to define your own subclass of \module{optparse}'s Option
-class.  This class has a couple of attributes that define \module{optparse}'s types:
-\member{TYPES} and \member{TYPE{\_}CHECKER}.
-
-\member{TYPES} is a tuple of type names; in your subclass, simply define a new
-tuple \member{TYPES} that builds on the standard one.
-
-\member{TYPE{\_}CHECKER} is a dictionary mapping type names to type-checking
-functions.  A type-checking function has the following signature:
-\begin{verbatim}
-def check_mytype(option, opt, value)
-\end{verbatim}
-
-where \code{option} is an \class{Option} instance, \code{opt} is an option string
-(e.g., \code{"-f"}), and \code{value} is the string from the command line that
-must be checked and converted to your desired type.  \code{check{\_}mytype()}
-should return an object of the hypothetical type \code{mytype}.  The value
-returned by a type-checking function will wind up in the OptionValues
-instance returned by \method{OptionParser.parse{\_}args()}, or be passed to a
-callback as the \code{value} parameter.
-
-Your type-checking function should raise OptionValueError if it
-encounters any problems.  OptionValueError takes a single string
-argument, which is passed as-is to OptionParser's \method{error()} method,
-which in turn prepends the program name and the string \code{"error:"} and
-prints everything to stderr before terminating the process.
-
-Here's a silly example that demonstrates adding a \code{complex} option
-type to parse Python-style complex numbers on the command line.  (This
-is even sillier than it used to be, because \module{optparse} 1.3 added built-in
-support for complex numbers, but never mind.)
-
-First, the necessary imports:
-\begin{verbatim}
-from copy import copy
-from optparse import Option, OptionValueError
-\end{verbatim}
-
-You need to define your type-checker first, since it's referred to later
-(in the \member{TYPE{\_}CHECKER} class attribute of your Option subclass):
-\begin{verbatim}
-def check_complex(option, opt, value):
-    try:
-        return complex(value)
-    except ValueError:
-        raise OptionValueError(
-            "option %s: invalid complex value: %r" % (opt, value))
-\end{verbatim}
-
-Finally, the Option subclass:
-\begin{verbatim}
-class MyOption (Option):
-    TYPES = Option.TYPES + ("complex",)
-    TYPE_CHECKER = copy(Option.TYPE_CHECKER)
-    TYPE_CHECKER["complex"] = check_complex
-\end{verbatim}
-
-(If we didn't make a \function{copy()} of \member{Option.TYPE{\_}CHECKER}, we would end
-up modifying the \member{TYPE{\_}CHECKER} attribute of \module{optparse}'s Option class.
-This being Python, nothing stops you from doing that except good manners
-and common sense.)
-
-That's it!  Now you can write a script that uses the new option type
-just like any other \module{optparse}-based script, except you have to instruct your
-OptionParser to use MyOption instead of Option:
-\begin{verbatim}
-parser = OptionParser(option_class=MyOption)
-parser.add_option("-c", type="complex")
-\end{verbatim}
-
-Alternately, you can build your own option list and pass it to
-OptionParser; if you don't use \method{add{\_}option()} in the above way, you
-don't need to tell OptionParser which option class to use:
-\begin{verbatim}
-option_list = [MyOption("-c", action="store", type="complex", dest="c")]
-parser = OptionParser(option_list=option_list)
-\end{verbatim}
-
-
-\subsubsection{Adding new actions\label{optparse-adding-new-actions}}
-
-Adding new actions is a bit trickier, because you have to understand
-that \module{optparse} has a couple of classifications for actions:
-\begin{description}
-\item[``store'' actions]
-actions that result in \module{optparse} storing a value to an attribute of the
-current OptionValues instance; these options require a \member{dest}
-attribute to be supplied to the Option constructor
-\item[``typed'' actions]
-actions that take a value from the command line and expect it to be
-of a certain type; or rather, a string that can be converted to a
-certain type.  These options require a \member{type} attribute to the
-Option constructor.
-\end{description}
-
-These are overlapping sets: some default ``store'' actions are \code{store},
-\code{store{\_}const}, \code{append}, and \code{count}, while the default ``typed''
-actions are \code{store}, \code{append}, and \code{callback}.
-
-When you add an action, you need to categorize it by listing it in at
-least one of the following class attributes of Option (all are lists of
-strings):
-\begin{description}
-\item[\member{ACTIONS}]
-all actions must be listed in ACTIONS
-\item[\member{STORE{\_}ACTIONS}]
-``store'' actions are additionally listed here
-\item[\member{TYPED{\_}ACTIONS}]
-``typed'' actions are additionally listed here
-\item[\code{ALWAYS{\_}TYPED{\_}ACTIONS}]
-actions that always take a type (i.e. whose options always take a
-value) are additionally listed here.  The only effect of this is
-that \module{optparse} assigns the default type, \code{string}, to options with no
-explicit type whose action is listed in \code{ALWAYS{\_}TYPED{\_}ACTIONS}.
-\end{description}
-
-In order to actually implement your new action, you must override
-Option's \method{take{\_}action()} method and add a case that recognizes your
-action.
-
-For example, let's add an \code{extend} action.  This is similar to the
-standard \code{append} action, but instead of taking a single value from
-the command-line and appending it to an existing list, \code{extend} will
-take multiple values in a single comma-delimited string, and extend an
-existing list with them.  That is, if \code{"-{}-names"} is an \code{extend}
-option of type \code{string}, the command line
-\begin{verbatim}
---names=foo,bar --names blah --names ding,dong
-\end{verbatim}
-
-would result in a list
-\begin{verbatim}
-["foo", "bar", "blah", "ding", "dong"]
-\end{verbatim}
-
-Again we define a subclass of Option:
-\begin{verbatim}
-class MyOption (Option):
-
-    ACTIONS = Option.ACTIONS + ("extend",)
-    STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",)
-    TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",)
-    ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",)
-
-    def take_action(self, action, dest, opt, value, values, parser):
-        if action == "extend":
-            lvalue = value.split(",")
-            values.ensure_value(dest, []).extend(lvalue)
-        else:
-            Option.take_action(
-                self, action, dest, opt, value, values, parser)
-\end{verbatim}
-
-Features of note:
-\begin{itemize}
-\item {} 
-\code{extend} both expects a value on the command-line and stores that
-value somewhere, so it goes in both \member{STORE{\_}ACTIONS} and
-\member{TYPED{\_}ACTIONS}
-
-\item {} 
-to ensure that \module{optparse} assigns the default type of \code{string} to
-\code{extend} actions, we put the \code{extend} action in
-\code{ALWAYS{\_}TYPED{\_}ACTIONS} as well
-
-\item {} 
-\method{MyOption.take{\_}action()} implements just this one new action, and
-passes control back to \method{Option.take{\_}action()} for the standard
-\module{optparse} actions
-
-\item {} 
-\code{values} is an instance of the optparse{\_}parser.Values class,
-which provides the very useful \method{ensure{\_}value()} method.
-\method{ensure{\_}value()} is essentially \function{getattr()} with a safety valve;
-it is called as
-\begin{verbatim}
-values.ensure_value(attr, value)
-\end{verbatim}
-
-If the \code{attr} attribute of \code{values} doesn't exist or is None, then
-ensure{\_}value() first sets it to \code{value}, and then returns 'value.
-This is very handy for actions like \code{extend}, \code{append}, and
-\code{count}, all of which accumulate data in a variable and expect that
-variable to be of a certain type (a list for the first two, an integer
-for the latter).  Using \method{ensure{\_}value()} means that scripts using
-your action don't have to worry about setting a default value for the
-option destinations in question; they can just leave the default as
-None and \method{ensure{\_}value()} will take care of getting it right when
-it's needed.
-
-\end{itemize}
-% $Id: extending.txt 517 2006-06-10 16:18:11Z gward $ 
-