Fix docstrings / scopes for python ThreeWidget

Author: vidartf

pythreejs/_base/Three.py

@@ -6,26 +6,35 @@
 
 
 class ThreeWidget(Widget):
+    """Base widget type for all pythreejs widgets"""
+
     _model_module = Unicode(npm_pkg_name).tag(sync=True)
     _model_module_version = Unicode(EXTENSION_VERSION).tag(sync=True)
 
     def __init__(self, **kwargs):
         super(ThreeWidget, self).__init__(**kwargs)
-        self.on_msg(self.on_potential_ret_val)
+        self.on_msg(self._on_potential_ret_val)
 
     def exec_three_obj_method(self, method_name, *args, **kwargs):
+        """Execute a method on the three object.
+
+        Excute the method specified by `method_name` on the three
+        object, with arguments `args`. `kwargs` is currently ignored.
+        """
         content = {
             "type": "exec_three_obj_method",
             "method_name": method_name,
             "args": widget_serialization['to_json'](args, None)
         }
         self.send(content=content, buffers=None)
 
-    def on_potential_ret_val(self, widget, content, buffers):
+    def _on_potential_ret_val(self, widget, content, buffers):
+        """Message callback used internally"""
         if content['type'] == "exec_three_obj_method_retval":
-            self.on_ret_val(content['method_name'], content['ret_val'])
+            self._on_ret_val(content['method_name'], content['ret_val'])
 
-    def on_ret_val(self, method_name, ret_val):
+    def _on_ret_val(self, method_name, ret_val):
+        """Message callback used internally for logging exec returns"""
         self.log.info('%s() -> %s' % (method_name, ret_val))
 
     def _ipython_display_(self, **kwargs):