#
# Instances of this class represent books. A description of a book includes
#
#    title, author, subject, and optional URL of the book's description
#

from string import split, strip

class Book:

	def __init__ (self, t="", a="", s="", u=""):
		#
		# Create an instance of Book
		#
		self.title = t
		self.last_name = []
		self.first_name = []
		self.set_author (a)
		self.subject = s
		self.url = u

	def set_author (self, new_author):
		#
		# Author's name is in "last_name, first_name" format
		#
		if new_author:
			names = split (new_author, ",")
			print (names[0])
			self.last_name.append (strip (names[0]))
			print (names[1])
			self.first_name.append (strip (names[1]))
		else:
			self.last_name = []
			self.first_name = []
			
	def set_title (self, new_title):
		self.title = new_title
		
			
	def set_subject (self, new_subject):
		self.subject = new_subject

	def set_url (self, new_url):
		self.url = new_url

	def display (self):
		print "Title  : " + self.title
		i = 0
		while i < len (self.first_name):
			print "Author : " + self.first_name[i] + " " + self.last_name[i]
			i = i + 1
		print "Subject: " + self.subject
		print "URL    : " + self.url

#
# Code to test this class
#
if __name__ == '__main__':
    print "**** Test 1 ****"
    b = Book()
    b.set_author ("Gann, Ernest")
    b.set_title ("Fate is the Hunter")
    b.set_subject ("General Aviation")
    b.display ()
    print "*** Test 2 ****"
    b = Book ("Fate is the Hunter", "Gann, Ernest")
    b.display ()
    print "*** Test 3 ****"
    b = Book ("Some book", "First, Author")
    b.set_author ("Seconf, Author")
    b.display ()
    print "*** Finish ***"