Update serializers.py

Author: Balaji Veeramani

src/sagemaker/serializers.py

@@ -212,12 +212,12 @@ def serialize(self, data):
         if isinstance(data, str):
             return data
 
-        if isinstance(data, Iterable):
-            return "\n".join(json.dumps(element) for element in data)
-
         if hasattr(data, "read"):
             return data.read()
 
+        if isinstance(data, Iterable):
+            return "\n".join(json.dumps(element) for element in data)
+
         raise ValueError("Object of type %s is not JSON Lines serializable." % type(data))