The argparse module makes it easy to write user-friendly command-line interfaces.

###
# argparse - Command line option and argument parsing.
#
## Argument Actions
#
# There are six built-in actions that can be triggered when an argument is
# encountered:
#
# store
#   Save the value, after optionally converting it to a different type. This is
#   the default action taken if none is specified expliclity.
#
# store_const
#   Save a value defined as part of the argument specification, rather than a
#   value that comes from the arguments being parsed. This is typically used to
#   implement command line flags that aren't booleans.
#
# store_true / store_false
#   Save the appropriate boolean value. These actions are used to implement
#   boolean switches.
#
# append
#   Save the value to a list. Multiple values are saved if the argument is
#   repeated.
#
# append_const
#   Save a value defined in the argument specification to a list.
#
# version
#   Prints version details about the program and then exits.
#
# source: https://pymotw.com/2/argparse/
###


import argparse

parser = argparse.ArgumentParser()

parser.add_argument('-s',
    action='store',
    dest='simple_value',
    help='Store a simple value'
)

parser.add_argument('-c',
    action='store_const',
    dest='constant_value',
    const='value-to-store',
    help='Store a constant value'
)

parser.add_argument('-t',
    action='store_true',
    default=False,
    dest='boolean_switch',
    help='Set a switch to true'
)

parser.add_argument('-f',
    action='store_false',
    default=False,
    dest='boolean_switch',
    help='Set a switch to false'
)

parser.add_argument('-a',
    action='append',
    dest='collection',
    default=[],
    help='Add repeated values to a list'
)

parser.add_argument('-A',
    action='append_const',
    dest='const_collection',
    const='value-1-to-append',
    default=[],
    help='Add different values to list'
)

parser.add_argument('-B',
    action='append_const',
    dest='const_collection',
    const='value-2-to-append',
    help='Add different values to list'
)

parser.add_argument('--version',
    action='version',
    version='%(prog)s 1.0'
)

results = parser.parse_args()
print 'simple_value     =', results.simple_value
print 'constant_value   =', results.constant_value
print 'boolean_switch   =', results.boolean_switch
print 'collection       =', results.collection
print 'const_collection =', results.const_collection