Listing 2. Option Handler, options.py

#! /usr/local/bin/python
import sys, getopt, string
def help_message():
    print '''options.py -- uses getopt to recognize options
Options: -h      -- displays this help message
       -a      -- expects an argument
       --file= -- expects an argument
       --view  -- doesn't necessarily expect an argument
       --version -- displays Python version'''
    sys.exit(0)
try:
    options, xarguments = getopt.getopt(sys.argv[1:], 
    'ha', ['file=', '--view', 'version'])
except getopt.error:
    print 'Error: You tried to use an unknown option or the 
    argument for an option that requires it was missing. Try 
    `options.py -h\' for more information.'
        sys.exit(0)
for a in options[:]:
    if a[0] == '-h':
        help_message()
for a in options[:]:
    if a[0] == '-a' and a[1] != '':
        print a[0]+' = '+a[1]
        options.remove(a)
        break
    elif a[0] == '-a' and a[1] == '':
        print '-a expects an argument'
        sys.exit(0)
for a in options[:]:
    if a[0] == '--file' and a[1] != '':
        print a[0]+' = '+a[1]
        options.remove(a)
        break
    elif a[0] == '--file' and a[1] == '':
        print '--file expects an argument'
        sys.exit(0)
for a in options[:]:
    if a[0] == '--view' and a[1] != '':
        print a[0]+' = '+a[1]
        options.remove(a)
        break
    elif a[0] == '--view' and a[1] == '':
        print '--view doesn\'t necessarily expects an argument...'
        options.remove(a)
        sys.exit(0)
for a in options[:]:
    if a[0] == '--version':
        print 'options version 0.0.001'
        sys.exit(0)
for a in options[:]:
    if a[0] == '--python-version':
        print 'Python '+sys.version
        sys.exit(0)