def path_to_tensor(path):

    img = image.load_img(path, target_size = (224,224))
    x= image.img_to_array(img)
    return np.expand_dims(x, axis=0)

def paths_to_tensor(paths):
    list_of_tensors = [path_to_tensor(path) for path in tqdm(paths)]
    return np.vstack(list_of_tensors)

train_tensors = paths_to_tensor(train_files).astype('float32')/255
valid_tensors = paths_to_tensor(valid_files).astype('float32')/255
test_tensors = paths_to_tensor(test_files).astype('float32')/255