fixed suboptimal usage of ipywidgets.Output widget

resolves manrajgrover#140

halo/halo_notebook.py

@@ -26,26 +26,23 @@ def _make_output_widget(self):
         from ipywidgets.widgets import Output
         return Output()
 
-    # TODO: using property and setter
-    def _output(self, text=''):
-        return ({'name': 'stdout', 'output_type': 'stream', 'text': text},)
-
     def clear(self):
         if not self.enabled:
             return self
 
         with self.output:
-            self.output.outputs += self._output('\r')
-            self.output.outputs += self._output(self.CLEAR_LINE)
+            print('\r', end="")
+            print(self.CLEAR_LINE, end="")
 
-        self.output.outputs = self._output()
         return self
 
     def _render_frame(self):
+        self.output.clear_output(wait=True)
         frame = self.frame()
         output = '\r{}'.format(frame)
+
         with self.output:
-            self.output.outputs += self._output(output)
+            print(output, end="")
 
     def start(self, text=None):
         if text is not None:
@@ -105,6 +102,8 @@ def stop_and_persist(self, symbol=' ', text=None):
             if self._placement == 'right' else
             (symbol, text)
         ][0])
+
+        self.output.clear_output(wait=True)
 
         with self.output:
-            self.output.outputs = self._output(output)
+            print(output, end="")