[PythonActor] manage the case inData is None

pypushflow/PythonActor.py

@@ -281,12 +281,13 @@ class PythonActor(AbstractActor):
                 self.error_handler.triggerOnError(inData=(None, oldInData))
         else:
             out_data = {}
-            for key, value in inData.items():
-                if key in self.in_data:
-                    if self.in_data[key] != value:
+            if inData is not None:
+                for key, value in inData.items():
+                    if key in self.in_data:
+                        if self.in_data[key] != value:
+                            out_data[key] = value
+                    else:
                         out_data[key] = value
-                else:
-                    out_data[key] = value
 
             for downStreamActor in self.listDownStreamActor:
                 downStreamActor.trigger((output_channel, inData))