fix #56

test/base/test_batch.py

@@ -22,9 +22,10 @@ def test_batch():
 
 def test_batch_over_batch():
     batch = Batch(a=[3, 4, 5], b=[4, 5, 6])
-    batch2 = Batch(b=batch, c=[6, 7, 8])
+    batch2 = Batch(c=[6, 7, 8], b=batch)
     batch2.b.b[-1] = 0
     print(batch2)
+    assert batch2.values()[-1] == batch2.c
     assert batch2[-1].b.b == 0
 
 

tianshou/data/batch.py

@@ -131,6 +131,10 @@ def keys(self) -> List[str]:
         return sorted([
             i for i in self.__dict__ if i[0] != '_'] + list(self._meta))
 
+    def values(self) -> List[Any]:
+        """Return self.values()."""
+        return [self[k] for k in self.keys()]
+
     def get(self, k: str, d: Optional[Any] = None) -> Union['Batch', Any]:
         """Return self[k] if k in self else d. d defaults to None."""
         if k in self.__dict__ or k in self._meta: