Assignment due week 3, Tues Oct 25, bring exercise to turn in (hardcopy)

 Required: Ch. 8, 9, 14
 Optional: http://docs.python.org/library/stdtypes.html#string-methods
            http://docs.python.org/howto/regex.html
            http://docs.python.org/howto/unicode.html
	    http://farmdev.com/talks/unicode/

 Exercise: Write a function named concordance that takes three
  arguments: a string, a file object for a file that is open for
  reading, and a file object for a file that is open for writing.  The
  function writes in the output file the line numbers and contents of all the lines
  in the input file where the string occurs.  Write the function in a module
  concordance.py that also opens the input and output files, calls the function,
  and closes the files.