"getopt" --- C-style parser for command line options
****************************************************

**Code source :** Lib/getopt.py

Obsolète depuis la version 3.13: The "getopt" module is *soft
deprecated* and will not be developed further; development will
continue with the "argparse" module.

Note:

  The "getopt" module is a parser for command line options whose API
  is designed to be familiar to users of the C "getopt()" function.
  Users who are unfamiliar with the C "getopt()" function or who would
  like to write less code and get better help and error messages
  should consider using the "argparse" module instead.

======================================================================

This module helps scripts to parse the command line arguments in
"sys.argv". It supports the same conventions as the Unix "getopt()"
function (including the special meanings of arguments of the form
'"-"' and '"--"').  Long options similar to those supported by GNU
software may be used as well via an optional third argument.

Ce module fournit deux fonctions et une exception :

getopt.getopt(args, shortopts, longopts=[])

   Parses command line options and parameter list.  *args* is the
   argument list to be parsed, without the leading reference to the
   running program. Typically, this means "sys.argv[1:]". *shortopts*
   is the string of option letters that the script wants to recognize,
   with options that require an argument followed by a colon ("':'")
   and options that accept an optional argument followed by two colons
   ("'::'"); i.e., the same format that Unix "getopt()" uses.

   Note:

     Unlike GNU "getopt()", after a non-option argument, all further
     arguments are considered also non-options. This is similar to the
     way non-GNU Unix systems work.

   *longopts*, if specified, must be a list of strings with the names
   of the long options which should be supported.  The leading "'--'"
   characters should not be included in the option name.  Long options
   which require an argument should be followed by an equal sign
   ("'='"). Long options which accept an optional argument should be
   followed by an equal sign and question mark ("'=?'"). To accept
   only long options, *shortopts* should be an empty string.  Long
   options on the command line can be recognized so long as they
   provide a prefix of the option name that matches exactly one of the
   accepted options.  For example, if *longopts* is "['foo', 'frob']",
   the option "--fo" will match as "--foo", but "--f" will not match
   uniquely, so "GetoptError" will be raised.

   La valeur de retour se compose de deux éléments : le premier est
   une liste de paires "(option, value)", la deuxième est la liste des
   arguments de programme laissés après que la liste d’options est été
   dépouillée (il s’agit d’une tranche de fin de *args*). Chaque paire
   option-valeur retournée a l’option comme premier élément, préfixée
   avec un trait d'union pour les options courtes (par exemple,
   "'-x'") ou deux tirets pour les options longues (par exemple, "'--
   long-option'"), et l’argument option comme deuxième élément, ou une
   chaîne vide si le option n’a aucun argument. Les options se
   trouvent dans la liste dans l’ordre dans lequel elles ont été
   trouvées, permettant ainsi plusieurs occurrences. Les options
   longues et courtes peuvent être mélangées.

   Modifié dans la version 3.14: Optional arguments are supported.

getopt.gnu_getopt(args, shortopts, longopts=[])

   Cette fonction fonctionne comme "getopt()", sauf que le mode de
   *scan* GNU est utilisé par défaut. Cela signifie que les arguments
   option et non-option peuvent être **intermixés**. La fonction
   "getopt()" arrête le traitement des options dès qu’un argument de
   non-option est rencontré.

   If the first character of the option string is "'+'", or if the
   environment variable "POSIXLY_CORRECT" is set, then option
   processing stops as soon as a non-option argument is encountered.

   If the first character of the option string is "'-'", non-option
   arguments that are followed by options are added to the list of
   option-and-value pairs as a pair that has "None" as its first
   element and the list of non-option arguments as its second element.
   The second element of the "gnu_getopt()" result is a list of
   program arguments after the last option.

   Modifié dans la version 3.14: Support for returning intermixed
   options and non-option arguments in order.

exception getopt.GetoptError

   This is raised when an unrecognized option is found in the argument
   list or when an option requiring an argument is given none. The
   argument to the exception is a string indicating the cause of the
   error.  For long options, an argument given to an option which does
   not require one will also cause this exception to be raised.  The
   attributes "msg" and "opt" give the error message and related
   option; if there is no specific option to which the exception
   relates, "opt" is an empty string.

exception getopt.error

   Alias pour "GetoptError" ; pour la rétrocompatibilité.

Un exemple utilisant uniquement les options de style UNIX :

   >>> import getopt
   >>> args = '-a -b -cfoo -d bar a1 a2'.split()
   >>> args
   ['-a', '-b', '-cfoo', '-d', 'bar', 'a1', 'a2']
   >>> optlist, args = getopt.getopt(args, 'abc:d:')
   >>> optlist
   [('-a', ''), ('-b', ''), ('-c', 'foo'), ('-d', 'bar')]
   >>> args
   ['a1', 'a2']

L’utilisation de noms d’options longs est tout aussi simple :

   >>> s = '--condition=foo --testing --output-file abc.def -x a1 a2'
   >>> args = s.split()
   >>> args
   ['--condition=foo', '--testing', '--output-file', 'abc.def', '-x', 'a1', 'a2']
   >>> optlist, args = getopt.getopt(args, 'x', [
   ...     'condition=', 'output-file=', 'testing'])
   >>> optlist
   [('--condition', 'foo'), ('--testing', ''), ('--output-file', 'abc.def'), ('-x', '')]
   >>> args
   ['a1', 'a2']

Optional arguments should be specified explicitly:

   >>> s = '-Con -C --color=off --color a1 a2'
   >>> args = s.split()
   >>> args
   ['-Con', '-C', '--color=off', '--color', 'a1', 'a2']
   >>> optlist, args = getopt.getopt(args, 'C::', ['color=?'])
   >>> optlist
   [('-C', 'on'), ('-C', ''), ('--color', 'off'), ('--color', '')]
   >>> args
   ['a1', 'a2']

The order of options and non-option arguments can be preserved:

   >>> s = 'a1 -x a2 a3 a4 --long a5 a6'
   >>> args = s.split()
   >>> args
   ['a1', '-x', 'a2', 'a3', 'a4', '--long', 'a5', 'a6']
   >>> optlist, args = getopt.gnu_getopt(args, '-x:', ['long='])
   >>> optlist
   [(None, ['a1']), ('-x', 'a2'), (None, ['a3', 'a4']), ('--long', 'a5')]
   >>> args
   ['a6']

In a script, typical usage is something like this:

   import getopt, sys

   def main():
       try:
           opts, args = getopt.getopt(sys.argv[1:], "ho:v", ["help", "output="])
       except getopt.GetoptError as err:
           # print help information and exit:
           print(err)  # will print something like "option -a not recognized"
           usage()
           sys.exit(2)
       output = None
       verbose = False
       for o, a in opts:
           if o == "-v":
               verbose = True
           elif o in ("-h", "--help"):
               usage()
               sys.exit()
           elif o in ("-o", "--output"):
               output = a
           else:
               assert False, "unhandled option"
       # ...

   if __name__ == "__main__":
       main()

Note that an equivalent command line interface could be produced with
less code and more informative help and error messages by using the
"argparse" module:

   import argparse

   if __name__ == '__main__':
       parser = argparse.ArgumentParser()
       parser.add_argument('-o', '--output')
       parser.add_argument('-v', dest='verbose', action='store_true')
       args = parser.parse_args()
       # ... do something with args.output ...
       # ... do something with args.verbose ..

Voir aussi:

  Module "argparse"
     Option de ligne de commande alternative et bibliothèque d’analyse
     d’arguments.
