Update models to enable save/load

qlib/contrib/model/pytorch_gats_ts.py

@@ -164,7 +164,7 @@ class GATs(Model):
         else:
             raise NotImplementedError("optimizer {} is not supported!".format(optimizer))
 
-        self._fitted = False
+        self.fitted = False
         self.GAT_model.to(self.device)
 
     def mse(self, pred, label):
@@ -297,7 +297,7 @@ class GATs(Model):
 
         # train
         self.logger.info("training...")
-        self._fitted = True
+        self.fitted = True
 
         for step in range(self.n_epochs):
             self.logger.info("Epoch%d:", step)
@@ -329,7 +329,7 @@ class GATs(Model):
             torch.cuda.empty_cache()
 
     def predict(self, dataset):
-        if not self._fitted:
+        if not self.fitted:
             raise ValueError("model is not fitted yet!")
 
         dl_test = dataset.prepare("test", col_set=["feature", "label"], data_key=DataHandlerLP.DK_I)