Merge pull request #2699 from activeloopai/fy_fix_data

Fix `.data()` for empty tensors

Author: FayazRahman

deeplake/api/tests/test_json.py

@@ -245,3 +245,10 @@ def upload(stuff, ds):
     assert ds.list.data()["value"] == items
     assert ds.list[0].list() == items[0]
     assert ds.list.list() == items
+
+
+def test_empty_json(memory_ds):
+    with memory_ds as ds:
+        ds.create_tensor("json", htype="json")
+
+    assert ds.json.data()["value"] == []

deeplake/api/tests/test_text.py

@@ -95,3 +95,10 @@ def test_text_tensor_append(memory_ds):
         for i in range(3):
             assert ds.x[i].data() == ds2.x[i].data()
             assert ds.y[i].data() == ds2.y[i].data()
+
+
+def test_empty_text(memory_ds):
+    with memory_ds as ds:
+        ds.create_tensor("text", htype="text")
+
+    assert ds.text.data()["value"] == []

deeplake/core/tensor.py

@@ -1437,9 +1437,17 @@ def _extract_value(self, htype: str, fetch_chunks: bool = False):
             raise Exception(f"Only supported for {htype} tensors.")
 
         if self.ndim == 1:
-            return self.numpy(fetch_chunks=fetch_chunks)[0]
+            data = self.numpy(fetch_chunks=fetch_chunks)
+            if len(data) == 0:
+                return []
+            else:
+                return data[0]
         else:
-            return [sample[0] for sample in self.numpy(aslist=True)]
+            data = self.numpy(aslist=True, fetch_chunks=fetch_chunks)
+            if len(data) == 0:
+                return []
+            else:
+                return [sample[0] for sample in data]
 
     def text(self, fetch_chunks: bool = False):
         """Return text data. Only applicable for tensors with 'text' base htype."""