data_dir = 'hotdog'
os.listdir(os.path.join(data_dir, "hotdog")) # ['train', 'test']
train_imgs = ImageFolder(os.path.join(data_dir, 'hotdog/train'))
test_imgs = ImageFolder(os.path.join(data_dir, 'hotdog/test'))
hotdogs = [train_imgs[i][0] for i in range(8)]
not_hotdogs = [train_imgs[-i-1][0] for i in range(8)] #not_hotdogs文件夹里从后面读回来
print(train_imgs[1]) #'tuple' object
print(train_imgs[1][0]) #'Image' object
d2l.show_images(hotdogs + not_hotdogs, 2, 8, scale=1.4)
请问train_imgs[i][0]和train_imgs[-i-1][0]代表的是数据集中哪些图片?