shows a simple example on how to use optparse module

optparse_exampe_1.py

#!/usr/bin/python

# shows a simple example on how to use optparse module
# works under python2.6.5

# usage 1: 
# python optparse_exampe_1.py -o output.txt
# usage 2: 
# python optparse_exampe_1.py --help
# usage 3:
# python optparse_exampe_1.py

# the source of this snippet is modified from Doug Hellmann's Python Module of The Week
# http://pymotw.com/2/optparse/index.html

import optparse

# set the parser options
parser = optparse.OptionParser()
parser.add_option('-o', '--output', 
                  # dest keeps the variable name "output_filename" 
                  # to store the value of the option '-o', for later usage.
                  dest="output_filename", 
                  default="default.out",
                  help="test help info",
                  )
parser.add_option('--version',
                  dest="version",
                  default=1.0,
                  type="float",
                  )

'''
with the parser-option settings added, now optparse can parse the options 
by parse_args()
the parse_args(), by default it uses sys.argv[1:] 
https://docs.python.org/2/library/optparse.html
'''
options, remainder = parser.parse_args()

print 'VERSION   :', options.version
print 'OUTPUT    :', options.output_filename
print 'REMAINING :', remainder