def METHOD_NAME(self, file_pattern, index):
    """
    Reads the file of the PSU
    :param file_pattern: The filename convention
    :param index: An integer, 1-based index of the PSU of which to query status
    :return: int
    """
    return_value = 0
    try:
        with open(self.psu_path + file_pattern.format(index), 'r') as file_to_read:
            return_value = int(file_to_read.read())
    except IOError:
        log_err("Read file {} failed".format(self.psu_path + file_pattern.format(index)))
        return 0
    return return_value