# L-21 MCS 260 Mon 15 Oct 2007 : books
#
# This module defines the formats in which we
# store the information of a book on file, e.g.:
#
# '1:2:Making Use of Python:'
# The format of a book is a string of 3 fields:
# (1) availability, (2) key, (3) title.

def pack(key,status,title):
   "returns the string with book information\n\
where key is the book identification number,\n\
      status is True or False for availability,\n\
      title is the title of the book"
   if status: s = '1:'
   else: s = '0:'
   s += '%d:' % key
   s += title + ':\n'
   return s

def get_status(s):
   "given a string with book information,\n\
returns True or False for the availability"
   L = s.split(':')
   return int(L[0]) == 1

def get_key(s):
   "given a string with book information,\n\
returns the identification number of the book"
   L = s.split(':')
   return int(L[1])

def get_title(s):
   "given a string with book information,\n\
returns the title of the book"
   L = s.split(':')
   return L[2]