diff --git a/packages/python/plotly/_plotly_utils/basevalidators.py b/packages/python/plotly/_plotly_utils/basevalidators.py
index d4bd8451cef..7e4bdc7bed0 100644
--- a/packages/python/plotly/_plotly_utils/basevalidators.py
+++ b/packages/python/plotly/_plotly_utils/basevalidators.py
@@ -1033,9 +1033,9 @@ class ColorValidator(BaseValidator):
             ]
         },
     """
-    re_hex = re.compile('#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})')
-    re_rgb_etc = re.compile('(rgb|hsl|hsv)a?\([\d.]+%?(,[\d.]+%?){2,3}\)')
-    re_ddk = re.compile('var\(\-\-.*\)')
+    re_hex = re.compile(r'#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})')
+    re_rgb_etc = re.compile(r'(rgb|hsl|hsv)a?\([\d.]+%?(,[\d.]+%?){2,3}\)')
+    re_ddk = re.compile(r'var\(\-\-.*\)')
 
     named_colors = [
         "aliceblue", "antiquewhite", "aqua", "aquamarine", "azure", "beige",
@@ -1456,9 +1456,9 @@ def __init__(self, plotly_name,
             self.base = dflt
         else:
             # e.g. regex == '/^y([2-9]|[1-9][0-9]+)?$/'
-            self.base = re.match('/\^(\w+)', regex).group(1)
+            self.base = re.match(r'/\^(\w+)', regex).group(1)
 
-        self.regex = self.base + "(\d*)"
+        self.regex = self.base + r"(\d*)"
 
     def description(self):
 
@@ -2268,6 +2268,8 @@ def description(self):
     that may be specified as:
       - A list or tuple of trace instances
         (e.g. [Scatter(...), Bar(...)])
+      - A single trace instance
+        (e.g. Scatter(...), Bar(...), etc.)
       - A list or tuple of dicts of string/value properties where:
         - The 'type' property specifies the trace type
 {trace_types}
@@ -2302,7 +2304,10 @@ def validate_coerce(self, v, skip_invalid=False):
 
         if v is None:
             v = []
-        elif isinstance(v, (list, tuple)):
+        else:
+            if not isinstance(v, (list, tuple)):
+                v = [v]
+
             trace_classes = tuple(self.class_map.values())
 
             res = []
@@ -2355,12 +2360,6 @@ def validate_coerce(self, v, skip_invalid=False):
                 for trace in v:
                     trace.uid = str(uuid.uuid4())
 
-        else:
-            if skip_invalid:
-                v = []
-            else:
-                self.raise_invalid_val(v)
-
         return v
 
 
diff --git a/packages/python/plotly/_plotly_utils/tests/validators/test_basetraces_validator.py b/packages/python/plotly/_plotly_utils/tests/validators/test_basetraces_validator.py
index 67c6be95b92..04cef14cb6e 100644
--- a/packages/python/plotly/_plotly_utils/tests/validators/test_basetraces_validator.py
+++ b/packages/python/plotly/_plotly_utils/tests/validators/test_basetraces_validator.py
@@ -84,7 +84,7 @@ def test_rejection_type(validator):
     with pytest.raises(ValueError) as validation_failure:
         validator.validate_coerce(val)
 
-    assert "Invalid value" in str(validation_failure.value)
+    assert "Invalid element(s)" in str(validation_failure.value)
 
 
 def test_rejection_element_type(validator):
diff --git a/packages/python/plotly/_plotly_utils/tests/validators/test_imageuri_validator.py b/packages/python/plotly/_plotly_utils/tests/validators/test_imageuri_validator.py
index ff22cbaf1d2..7264cf69d23 100644
--- a/packages/python/plotly/_plotly_utils/tests/validators/test_imageuri_validator.py
+++ b/packages/python/plotly/_plotly_utils/tests/validators/test_imageuri_validator.py
@@ -1,8 +1,8 @@
 import base64
-
+import os
 import pytest
 from _plotly_utils.basevalidators import ImageUriValidator
-import numpy as np
+
 from PIL import Image
 
 
@@ -28,7 +28,9 @@ def test_validator_acceptance(val, validator):
 def test_validator_coercion_PIL(validator):
     # Single pixel black png (http://png-pixel.com/)
 
-    img_path = '_plotly_utils/tests/resources/1x1-black.png'
+    tests_dir = os.path.dirname(os.path.dirname(__file__))
+    img_path = os.path.join(tests_dir, 'resources', '1x1-black.png')
+
     with open(img_path, 'rb') as f:
         hex_bytes = base64.b64encode(f.read()).decode('ascii')
         expected_uri = 'data:image/png;base64,' + hex_bytes
diff --git a/packages/python/plotly/plotly/basedatatypes.py b/packages/python/plotly/plotly/basedatatypes.py
index 1d631763ea0..0a09447b239 100644
--- a/packages/python/plotly/plotly/basedatatypes.py
+++ b/packages/python/plotly/plotly/basedatatypes.py
@@ -498,6 +498,37 @@ def update(self, dict1=None, **kwargs):
                             self[k] = v
         return self
 
+    def pop(self, key, *args):
+        """
+        Remove the value associated with the specified key and return it
+
+        Parameters
+        ----------
+        key: str
+            Property name
+        dflt
+            The default value to return if key was not found in figure
+
+        Returns
+        -------
+        value
+            The removed value that was previously associated with key
+
+        Raises
+        ------
+        KeyError
+            If key is not in object and no dflt argument specified
+        """
+        # Handle default
+        if key not in self and args:
+            return args[0]
+        elif key in self:
+            val = self[key]
+            self[key] = None
+            return val
+        else:
+            raise KeyError(key)
+
     # Data
     # ----
     @property
@@ -520,6 +551,10 @@ def data(self, new_data):
                       'a list or tuple that contains a permutation of a '
                       'subset of itself.\n')
 
+        # ### Treat None as empty ###
+        if new_data is None:
+            new_data = ()
+
         # ### Check valid input type ###
         if not isinstance(new_data, (list, tuple)):
             err_msg = (err_header + '    Received value with type {typ}'
@@ -859,6 +894,29 @@ def update_traces(
             trace.update(patch, **kwargs)
         return self
 
+    def update_layout(self, dict1=None, **kwargs):
+        """
+        Update the properties of the figure's layout with a dict and/or with
+        keyword arguments.
+
+        This recursively updates the structure of the original
+        layout with the values in the input dict / keyword arguments.
+
+        Parameters
+        ----------
+        dict1 : dict
+            Dictionary of properties to be updated
+        kwargs :
+            Keyword/value pair of properties to be updated
+
+        Returns
+        -------
+        BaseFigure
+            The Figure object that the update_layout method was called on
+        """
+        self.layout.update(dict1, **kwargs)
+        return self
+
     def _select_layout_subplots_by_prefix(
             self,
             prefix,
@@ -3480,6 +3538,37 @@ def update(self, dict1=None, **kwargs):
 
         return self
 
+    def pop(self, key, *args):
+        """
+        Remove the value associated with the specified key and return it
+
+        Parameters
+        ----------
+        key: str
+            Property name
+        dflt
+            The default value to return if key was not found in object
+
+        Returns
+        -------
+        value
+            The removed value that was previously associated with key
+
+        Raises
+        ------
+        KeyError
+            If key is not in object and no dflt argument specified
+        """
+        # Handle default
+        if key not in self and args:
+            return args[0]
+        elif key in self:
+            val = self[key]
+            self[key] = None
+            return val
+        else:
+            raise KeyError(key)
+
     @property
     def _in_batch_mode(self):
         """
diff --git a/packages/python/plotly/plotly/graph_objects.py b/packages/python/plotly/plotly/graph_objects.py
new file mode 100644
index 00000000000..406bd66fd8d
--- /dev/null
+++ b/packages/python/plotly/plotly/graph_objects.py
@@ -0,0 +1,2 @@
+from __future__ import absolute_import
+from plotly.graph_objs import *
diff --git a/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_append_trace.py b/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_append_trace.py
index 40e5ac759ac..d90b8893408 100644
--- a/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_append_trace.py
+++ b/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_append_trace.py
@@ -111,22 +111,6 @@ def test_append_scatter():
     assert d1 == d2
 
 
-@raises(Exception)
-def test_append_scatter_after_deleting_xaxis():
-    trace = Scatter(x=[1, 2, 3], y=[2, 3, 4])
-    fig = tls.make_subplots(rows=2, cols=3)
-    fig['layout'].pop('xaxis5', None)
-    fig.append_trace(trace, 2, 2)
-
-
-@raises(Exception)
-def test_append_scatter_after_deleting_yaxis():
-    trace = Scatter(x=[1, 2, 3], y=[2, 3, 4])
-    fig = tls.make_subplots(rows=2, cols=3)
-    fig['layout'].pop('yaxis5', None)
-    fig.append_trace(trace, 2, 2)
-
-
 def test_append_scatter3d():
     expected = Figure(
         data=Data([
@@ -168,13 +152,3 @@ def test_append_scatter3d():
 
     d1, d2 = strip_dict_params(fig['layout'], expected['layout'])
     assert d1 == d2
-
-
-@raises(Exception)
-def test_append_scatter3d_after_deleting_scene():
-    fig = tls.make_subplots(rows=2, cols=1,
-                            specs=[[{'is_3d': True}],
-                                   [{'is_3d': True}]])
-    trace = Scatter3d(x=[1, 2, 3], y=[2, 3, 4], z=[1, 2, 3])
-    fig['layout'].pop('scene1', None)
-    fig.append_trace(trace, 1, 1)
diff --git a/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_figure.py b/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_figure.py
index c38cef4a9fc..527ee0dc85c 100644
--- a/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_figure.py
+++ b/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_figure.py
@@ -1,6 +1,6 @@
 from __future__ import absolute_import
 
-import plotly.graph_objs as go
+import plotly.graph_objects as go
 from plotly.tests.utils import TestCaseNoTemplate
 
 
@@ -139,3 +139,25 @@ def test_add_trace_underscore_kwarg(self):
         fig.add_scatter(y=[2, 1, 3], marker_line_color='green')
 
         self.assertEqual(fig.data[0].marker.line.color, 'green')
+
+    def test_scalar_trace_as_data(self):
+        fig = go.Figure(data=go.Waterfall(y=[2, 1, 3]))
+        self.assertEqual(fig.data, (go.Waterfall(y=[2, 1, 3]),))
+
+        fig = go.Figure(data=dict(type='waterfall', y=[2, 1, 3]))
+        self.assertEqual(fig.data, (go.Waterfall(y=[2, 1, 3]),))
+
+    def test_pop_data(self):
+        fig = go.Figure(data=go.Waterfall(y=[2, 1, 3]))
+        self.assertEqual(fig.pop('data'), (go.Waterfall(y=[2, 1, 3]),))
+        self.assertEqual(fig.data, ())
+
+    def test_pop_layout(self):
+        fig = go.Figure(layout=go.Layout(width=1000))
+        self.assertEqual(fig.pop('layout'), go.Layout(width=1000))
+        self.assertEqual(fig.layout, go.Layout())
+
+    def test_pop_invalid_key(self):
+        fig = go.Figure(layout=go.Layout(width=1000))
+        with self.assertRaises(KeyError):
+            fig.pop('bogus')
diff --git a/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_graph_objs.py b/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_graph_objs.py
index 004ef74e8ee..2cf2f4ded78 100644
--- a/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_graph_objs.py
+++ b/packages/python/plotly/plotly/tests/test_core/test_graph_objs/test_graph_objs.py
@@ -115,3 +115,40 @@ def test_legacy_title_props_remapped(self):
         self.assertIn('titlefont', obj)
         self.assertIn('titlefont.family', obj)
         self.assertIn('titlefont', iter(obj))
+
+
+class TestPop(TestCase):
+    def setUp(self):
+        self.layout = go.Layout(
+            width=1000,
+            title={'text': 'the title', 'font': {'size': 20}},
+            annotations=[{}, {}],
+            xaxis2={'range': [1, 2]}
+        )
+
+    def test_pop_valid_simple_prop(self):
+        self.assertEqual(self.layout.width, 1000)
+        self.assertEqual(self.layout.pop('width'), 1000)
+        self.assertIsNone(self.layout.width)
+
+    def test_pop_valid_compound_prop(self):
+        val = self.layout.title
+        self.assertEqual(self.layout.pop('title'), val)
+        self.assertEqual(self.layout.title, go.layout.Title())
+
+    def test_pop_valid_array_prop(self):
+        val = self.layout.annotations
+        self.assertEqual(self.layout.pop('annotations'), val)
+        self.assertEqual(self.layout.annotations, ())
+
+    def test_pop_valid_subplot_prop(self):
+        val = self.layout.xaxis2
+        self.assertEqual(self.layout.pop('xaxis2'), val)
+        self.assertEqual(self.layout.xaxis2, go.layout.XAxis())
+
+    def test_pop_invalid_prop_key_error(self):
+        with self.assertRaises(KeyError):
+            self.layout.pop('bogus')
+
+    def test_pop_invalid_prop_with_default(self):
+        self.assertEqual(self.layout.pop('bogus', 42), 42)
\ No newline at end of file
diff --git a/packages/python/plotly/plotly/tests/test_core/test_update_objects/test_update_layout.py b/packages/python/plotly/plotly/tests/test_core/test_update_objects/test_update_layout.py
new file mode 100644
index 00000000000..1b152191c04
--- /dev/null
+++ b/packages/python/plotly/plotly/tests/test_core/test_update_objects/test_update_layout.py
@@ -0,0 +1,29 @@
+from unittest import TestCase
+import plotly.graph_objects as go
+
+
+class TestUpdateLayout(TestCase):
+
+    def test_update_layout_kwargs(self):
+        # Create initial figure
+        fig = go.Figure()
+        fig.layout.title.font.size = 10
+
+        # Grab copy of original figure
+        orig_fig = go.Figure(fig)
+
+        fig.update_layout(title_font_family='Courier New')
+        orig_fig.layout.update(title_font_family='Courier New')
+        self.assertEqual(fig, orig_fig)
+
+    def test_update_layout_dict(self):
+        # Create initial figure
+        fig = go.Figure()
+        fig.layout.title.font.size = 10
+
+        # Grab copy of original figure
+        orig_fig = go.Figure(fig)
+
+        fig.update_layout(dict(title=dict(font=dict(family='Courier New'))))
+        orig_fig.layout.update(title_font_family='Courier New')
+        self.assertEqual(fig, orig_fig)
diff --git a/packages/python/plotly/plotly/tests/test_orca/test_to_image.py b/packages/python/plotly/plotly/tests/test_orca/test_to_image.py
index d57d84bdfec..156ccc58237 100644
--- a/packages/python/plotly/plotly/tests/test_orca/test_to_image.py
+++ b/packages/python/plotly/plotly/tests/test_orca/test_to_image.py
@@ -321,7 +321,7 @@ def test_invalid_figure_json():
     with pytest.raises(ValueError) as err:
         pio.to_image(bad_fig, format='png')
 
-    assert "Invalid value of type" in str(err.value)
+    assert "Invalid" in str(err.value)
 
     with pytest.raises(ValueError) as err:
         pio.to_image(bad_fig, format='png', validate=False)
diff --git a/packages/python/plotly/plotlywidget/__init__.py b/packages/python/plotly/plotlywidget/__init__.py
new file mode 100644
index 00000000000..421e7990307
--- /dev/null
+++ b/packages/python/plotly/plotlywidget/__init__.py
@@ -0,0 +1,9 @@
+def _jupyter_nbextension_paths():
+    return [{
+        'section': 'notebook',
+        'src': 'static',
+        'dest': 'plotlywidget',
+        'require': 'plotlywidget/extension'
+    }]
+
+__frontend_version__ = '^0.1'