def check_file_isvid(filename):
    """
    checks if a file has a video extension, accepted files are: '.mp4', '.mpg', '.avi'
    :param filename: (str) name of the file
    :return: (bool)
    """
    list_extensions = ['.mpg', '.MPG', '.mp4', '.MP4', '.AVI', '.avi']
    if filename[-4:] in list_extensions:
        return True
    else:
        return False