Python tutorial and start up script

tutorial:

http://docs.python.org/tutorial/index.html

http://net.tutsplus.com/tutorials/python-tutorials/python-from-scratch-object-oriented-programming/

xml:
http://www.learningpython.com/2008/05/07/elegant-xml-parsing-using-the-elementtree-module/

start up script:

http://stackoverflow.com/questions/5359306/set-and-require-default-python-script-optionparser

from optparse import OptionParser
import sys
def main():
   usage = "usage: %prog [options] arg"
   parser = OptionParser(usage)
   parser.add_option('-d', '--directory',
           action='store', dest='directory',
           default=None, help='specify directory')
   parser.add_option('-f', '--file',
           action='store', dest='filename',
           default=None, help='specify file')
   parser.add_option('-v', '--version',
                     action="store_true", dest="show_version",
                     default=False, help='displays the version number')
   if len(sys.argv) == 1:
       parser.print_help()
       sys.exit()
   (options, args) = parser.parse_args()
   # rest of program...
if __name__ == '__main__':
   main()