Loads extraction rules from the specified file.

        @fname - Path to the extraction rule file.

        Returns None.

def load_from_file(self, fname):
        '''
        Loads extraction rules from the specified file.

        @fname - Path to the extraction rule file.

        Returns None.
        '''
        try:
            # Process each line from the extract file, ignoring comments
            with open(fname, 'r') as f:
                for rule in f.readlines():
                    self.add_rule(rule.split(self.COMMENT_DELIM, 1)[0])
        except KeyboardInterrupt as e:
            raise e
        except Exception as e:
            raise Exception("Extractor.load_from_file failed to load file '%s': %s" % (fname, str(e)))