CIFAR10无法转转换维度，torchvision.tranforms.ToTensor没用

train_data = torchvision.datasets.CIFAR10(
    root='./cifar10/',
    train=True,
    transform=torchvision.transforms.ToTensor(),
    download=DOWNLOAD_CIFAR
)
#无法使用print(train_data.data.size())  #nparray 没有.size()
print(train_data.data.shape)  #输出train_data数据维度  
#(50000, 32, 32, 3)
按理说应该是(50000, 3, 32, 32)