Get the annotator name list based on a list of files
    Args:
    file_dir: AMR file folder
    files: a list of AMR names, e.g. nw_wsj_0001_1

    Returns:
   a list of user names who annotate all the files

def get_names(file_dir, files):
    """
    Get the annotator name list based on a list of files
    Args:
    file_dir: AMR file folder
    files: a list of AMR names, e.g. nw_wsj_0001_1

    Returns:
   a list of user names who annotate all the files
    """
    # for each user, check if they have files available
    # return user name list
    total_list = []
    name_list = []
    get_sub = False
    for path, subdir, dir_files in os.walk(file_dir):
        if not get_sub:
            total_list = subdir[:]
            get_sub = True
        else:
            break
    for user in total_list:
        has_file = True
        for f in files:
            file_path = file_dir + user + "/" + f + ".txt"
            if not os.path.exists(file_path):
                has_file = False
                break
        if has_file:
            name_list.append(user)
    if len(name_list) == 0:
        print("********Error: Cannot find any user who completes the files*************", file=ERROR_LOG)
    return name_list