import osimport randomrootdir = "d://face//train"file_names = []for parent, dirnames, filenames in os.walk(rootdir):  #三個參數：分別返回1.父目錄 2.所有文件夾名字（不含路徑） 3.所有文件名字  file_names = filenames  # for filename in filenames:            #輸出文件信息  #   print("parent is" + parent)  #   print("filename is:" + filename)  #   print("the full name of the file is:" + os.path.join(parent, filename))x = random.randint(0, len(file_names)-1)print(file_names[x])