错误描述

pytorch在自定义dataset CELEBA类的时候，用到了以下表达：

class CELEBA(DatasetFolder):

    def __init__(
            self,
            root: str,
            transform: Optional[Callable] = None,
            target_transform: Optional[Callable] = None,
            loader: Callable[[str], Any] = default_loader,
            is_valid_file: Optional[Callable[[str], bool]] = None,
    ):
        super(CELEBA, self).__init__(root, loader, IMG_EXTENSIONS if is_valid_file is None else None,
                                          transform=transform,
                                          target_transform=target_transform,
                                          is_valid_file=is_valid_file)
        self.imgs = self.samples

        self.onehot_targets = encode_onehot(self.targets, 10177)  # 50 10177

错误信息：

~/SageMaker/dsdh/data/celeba.py in CELEBA()
63 target_transform: Optional[Callable] = None,
64 loader: Callable[[str], Any] = default_loader,
—> 65 is_valid_file: Optional[Callable[[str], bool]] = None,
66 ):
67 super(CELEBA, self).init(root, loader, IMG_EXTENSIONS if is_valid_file is None else None,

NameError: name ‘Optional’ is not defined

解决方法

from typing import Optional, Callable, Any, Tuple