<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def read(self, filename):
 """ Reads the file specified and tokenizes the data for parsing. """


        try:
            with open(filename, 'r') as _file:
                self._filename = filename
                self.readstream(_file)
            return True

        except IOError:
            self._filename = None
            return False