import platform
from torchvision.datasets import ImageFolder


class Check(object):
? ? def __init__(self,
? ? ? ? ? ? ? ? ?key_word: str):
? ? ? ? self.key_word = key_word
? ? ? ? self.separator = '\\' if platform.system() == 'Windows' else '/'

? ? def __call__(self,?
? ? ?? ??? ??? ? file_name: str) -> bool:
? ? ? ? folders = file_name.split(self.separator)
? ? ? ? return folders[-1].find(self.key_word) < 0

dataset = ImageFolder('./data', is_valid_file=Check('invalid'))

from torchvision.datasets.folder import *
from typing import *


class FilterableImageFolder(ImageFolder):
? ? 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,
? ? ? ? ? ? valid_classes: List = None
? ? ):
? ? ? ? self.valid_classes = valid_classes
? ? ? ? super(FilterableImageFolder, self).__init__(root, transform, target_transform, loader, is_valid_file)

? ? def find_classes(self, directory: str) -> Tuple[List[str], Dict[str, int]]:
? ? ? ? classes = sorted(entry.name for entry in os.scandir(directory) if entry.is_dir())
? ? ? ? #增加了這下面這句
? ? ? ? classes = [valid_class for valid_class in classes if valid_class in self.valid_classes]
? ? ? ? if not classes:
? ? ? ? ? ? raise FileNotFoundError(f"Couldn't find any class folder in {directory}.")

? ? ? ? class_to_idx = {cls_name: i for i, cls_name in enumerate(classes)}
? ? ? ? return classes, class_to_idx

dataset = FilterableImageFolder('./data', valid_classes=['cat', 'dog'])