File: class/Extras/Code/XML/bookhandler.py

################################
# SAX is a callback-based API 
# for intercepting parser events
################################
import xml.sax.handler
class BookHandler(xml.sax.handler.ContentHandler):
 def __init__(self):
 self.inTitle = 0 # handle xml parser events
 self.mapping = {} # a state machine model
 def startElement(self, name, attributes):
 if name == "book": # on start book tag
 self.buffer = "" # save isbn for dict key
 self.isbn = attributes["isbn"] 
 elif name == "title": # on start title tag
 self.inTitle = 1 # save title text to follow
 def characters(self, data):
 if self.inTitle: # on text within tag
 self.buffer += data # save text if in title
 def endElement(self, name):
 if name == "title":
 self.inTitle = 0 # on end title tag
 self.mapping[self.isbn] = self.buffer # store title text in dict