added deepsad base code

Deep-SAD-PyTorch/src/base/base_dataset.py

@@ -0,0 +1,26 @@
+from abc import ABC, abstractmethod
+from torch.utils.data import DataLoader
+
+
+class BaseADDataset(ABC):
+    """Anomaly detection dataset base class."""
+
+    def __init__(self, root: str):
+        super().__init__()
+        self.root = root  # root path to data
+
+        self.n_classes = 2  # 0: normal, 1: outlier
+        self.normal_classes = None  # tuple with original class labels that define the normal class
+        self.outlier_classes = None  # tuple with original class labels that define the outlier class
+
+        self.train_set = None  # must be of type torch.utils.data.Dataset
+        self.test_set = None  # must be of type torch.utils.data.Dataset
+
+    @abstractmethod
+    def loaders(self, batch_size: int, shuffle_train=True, shuffle_test=False, num_workers: int = 0) -> (
+            DataLoader, DataLoader):
+        """Implement data loaders of type torch.utils.data.DataLoader for train_set and test_set."""
+        pass
+
+    def __repr__(self):
+        return self.__class__.__name__