def is_valid_ext(f_name, cfg, log, **kwargs):

    """Function:  is_valid_ext

    Description:  Determine if the file extension is part of a list of
        extensions to be ignored.

    Arguments:
        (input) f_name -> File name.
        (input) cfg -> Configuration settings module for the program.
        (input) log -> Log class instance.
        (output) Status -> True|False - File extension is valid.

    """

    log.log_info("is_valid_ext:  Validating file extension...")
    status = True

    for ext in cfg.ignore_ext:
        if ext in f_name:
            log.log_warn("File extension invalid for: %s" % (f_name))
            status = False
            break

    return status