Merge pull request #2 from jasongrout/fix_widgets_and_widget_types

Move internal references to relative imports, add migration note

Author: maartenbreddels

docs/source/user_migration_guides.md

@@ -78,6 +78,10 @@ The previously deprecated traits `overflow_x` and `overflow_y`
 [have been removed](https://github.com/jupyter-widgets/ipywidgets/pull/2688). Please
 use the `overflow` trait instead.
 
+#### `Widget.widgets` and `Widget.widget_types` attributes
+
+The `Widget` class attributes `.widgets` and `.widget_types` are now deprecated and relocated to internal module-level private variables, opening up these attribute names on the `Widget` class for future uses.
+
 ### Deployments
 
 #### Embedded CDN

python/ipywidgets/ipywidgets/embed.py

@@ -12,8 +12,7 @@
 
 import json
 import re
-import ipywidgets.widgets.widget
-from .widgets import Widget, DOMWidget
+from .widgets import Widget, DOMWidget, widget as widget_module
 from .widgets.widget_link import Link
 from .widgets.docutils import doc_subst
 from ._version import __html_manager_version__
@@ -130,7 +129,7 @@ def _get_recursive_state(widget, store=None, drop_defaults=False):
 
 def add_resolved_links(store, drop_defaults):
     """Adds the state of any link models between two models in store"""
-    for widget_id, widget in ipywidgets.widgets.widget._instances.items(): # go over all widgets
+    for widget_id, widget in widget_module._instances.items(): # go over all widgets
         if isinstance(widget, Link) and widget_id not in store:
             if widget.source[0].model_id in store and widget.target[0].model_id in store:
                 store[widget.model_id] = widget._get_embed_state(drop_defaults=drop_defaults)
@@ -208,7 +207,7 @@ def embed_data(views, drop_defaults=True, state=None):
         view_specs: a list of widget view specs
     """
     if views is None:
-        views = [w for w in ipywidgets.widgets.widget._instances.values() if isinstance(w, DOMWidget)]
+        views = [w for w in widget_module._instances.values() if isinstance(w, DOMWidget)]
     else:
         try:
             views[0]

python/ipywidgets/ipywidgets/tests/test_embed.py

@@ -9,8 +9,7 @@
 
 import traitlets
 
-import ipywidgets.widgets.widget
-from ..widgets import IntSlider, IntText, Text, Widget, jslink, HBox, widget_serialization
+from ..widgets import IntSlider, IntText, Text, Widget, jslink, HBox, widget_serialization, widget as widget_module
 from ..embed import embed_data, embed_snippet, embed_minimal_html, dependency_state
 
 
@@ -30,7 +29,7 @@ class CaseWidget(Widget):
 class TestEmbed:
 
     def teardown(self):
-        for w in tuple(ipywidgets.widgets.widget._instances.values()):
+        for w in tuple(widget_module._instances.values()):
             w.close()
 
     def test_embed_data_simple(self):