fix unittest

Author: Cathy0908

tests/tools/test_process_data.py

@@ -182,12 +182,16 @@ def test_ray_image(self):
 
         self.assertTrue(osp.exists(tmp_out_path))
 
-        import ray
-        res_ds = ray.data.read_json(tmp_out_path)
-        res_ds = res_ds.to_pandas().to_dict(orient='records')
-
-        self.assertEqual(len(res_ds), 3)
-        for item in res_ds:
+        from datasets import load_dataset
+        jsonl_files = [os.path.join(tmp_out_path, f) \
+                       for f in os.listdir(tmp_out_path) \
+                        if f.endswith('.json')]
+        dataset = load_dataset(
+            'json',
+            data_files={'jsonl': jsonl_files})
+
+        self.assertEqual(len(dataset['jsonl']), 3)
+        for item in dataset['jsonl']:
             self.assertIn('aspect_ratios', item['__dj__stats__'])