code: def write_blacklist (self):
          
          oldmask = os.umask(0077)
          for key, value in self.blacklist.items():
              self.write(u"%d %s%s" % (value, repr(key), os.linesep))
          self.close_fileoutput()
          # restore umask
          os.umask(oldmask)
docs: Write the blacklist.