Returns a case from a version 30 PSS/E raw file.

        @param file_or_filename: File name or file like object with PSS/E data
        @return: Case object

def read(self, file_or_filename):
        """ Returns a case from a version 30 PSS/E raw file.

        @param file_or_filename: File name or file like object with PSS/E data
        @return: Case object
        """
        t0 = time.time()
        self.init()
        if isinstance(file_or_filename, basestring):
            fname = os.path.basename(file_or_filename)
            logger.info("Loading PSS/E Raw file [%s]." % fname)

            file = None
            try:
                file = open(file_or_filename, "rb")
            except:
                logger.error("Error opening %s." % fname)
                return None
            finally:
                if file is not None:
                    case = self._parse_file(file)
                    file.close()
        else:
            file = file_or_filename
            case = self._parse_file(file)

        logger.info("PSS/E Raw file parsed in %.2fs." % (time.time() - t0))

        return case