plotly.io HTML functions, modular renderers framework, future flags system (#1474)

* plotly.io.renderers implementation
* Use _repr_mimebundle_ to automatically display figures on repr in the Jupyter Notebook.
* Browser renderers to show figure in browser tabs.  Avoids writing out tmp file by create single use web server to serve the html content to the browser.
* Expose renderer base classes
* Auto-detect VSCode, Kaggle, and Colab environments and initialize renderer appropriately
* Added IFrameRenderer. Use include_plotlyjs='directory' for iframe renderer.
* Added initial to_html functions to plotly.io
* Reimplement plotly.offline.plot using plotly.io.write_html/to_div. Updated tests only slightly to reflect the change in how resizing is handled now. Before there was a custom callback resize script, now
we rely on the plotly.js 'responsive' config option
* Reimplement plotly.offline.iplot and init_notebook_mode pio.show
* Add responsive=True config when figure width/height aren't set
* Add MathJax configuration when initializing HTML renderer in notebook
* Reimplement HTML Renderers using the plotly.io html functions
* Add support for custom JS snippets in exported HTML. Now there is a post_script argument to the HTML functions that allows a user to specify some custom JavaScript to run after plot creation. This can be used by plot/iplot to implement the previous save image behavior without needing to add explicit save image options to the HTML functions.
* Remove default renderer and make rendering figure on display an option
that is false by default. Now the behavior of figure display, init_notebook_mode, iplot, and plot
are all backward compatible by default.
* Added future flag system under _plotly_future_ to control
default renderer settings and default template.
* Remove legacy unused _plot_html function
* Move combination renderers test to orca test suite
* Add ipython to orca environment for renderer tests
* Added chromium browser renderer
* Fix plotly mimetype renderer when used with numpy arrays/pandas Series
* Lazily initialize default renderers. This way we can keep notebook_connected as a default renderer, but it won't attempt notebook initialization unless in is explicitly shown. So this won't happen, for example, when using plotly.py in a Dash app
* Use 'browser' default renderer if ipython isn't available
* Trigger notebook renderer activation on `init_notebook_mode` call. This will improve backward compatibility with the legacy init_notebook_mode() function.

Author: jonmmease

Diff for: .circleci/create_conda_optional_env.sh

@@ -16,7 +16,7 @@ if [ ! -d $HOME/miniconda/envs/circle_optional ]; then
     # Create environment
     # PYTHON_VERSION=3.6
     $HOME/miniconda/bin/conda create -n circle_optional --yes python=$PYTHON_VERSION \
-requests six pytz retrying psutil pandas decorator pytest mock nose poppler xarray scikit-image
+requests six pytz retrying psutil pandas decorator pytest mock nose poppler xarray scikit-image ipython
 
     # Install orca into environment
     $HOME/miniconda/bin/conda install --yes -n circle_optional -c plotly plotly-orca

Diff for: _plotly_future_/__init__.py

@@ -0,0 +1,8 @@
+_future_flags = set()
+
+
+def _assert_plotly_not_imported():
+    import sys
+    if 'plotly' in sys.modules:
+        raise ImportError("""\
+The _plotly_future_ module must be imported before the plotly module""")

Diff for: _plotly_future_/renderer_defaults.py

@@ -0,0 +1,5 @@
+from __future__ import absolute_import
+from _plotly_future_ import _future_flags, _assert_plotly_not_imported
+
+_assert_plotly_not_imported()
+_future_flags.add('renderer_defaults')

Diff for: _plotly_future_/template_defaults.py

@@ -0,0 +1,5 @@
+from __future__ import absolute_import
+from _plotly_future_ import _future_flags, _assert_plotly_not_imported
+
+_assert_plotly_not_imported()
+_future_flags.add('template_defaults')

Diff for: _plotly_future_/v4.py

@@ -0,0 +1,2 @@
+from __future__ import absolute_import
+from _plotly_future_ import renderer_defaults, template_defaults

Diff for: plotly/__init__.py

@@ -31,7 +31,13 @@
 from plotly import (plotly, dashboard_objs, graph_objs, grid_objs, tools,
                     utils, session, offline, colors, io)
 from plotly.version import __version__
+from _plotly_future_ import _future_flags
 
 from ._version import get_versions
 __version__ = get_versions()['version']
 del get_versions
+
+# Set default template here to make sure import process is complete
+if 'template_defaults' in _future_flags:
+    # Set _default to skip validation
+    io.templates._default = 'plotly'

Diff for: plotly/basedatatypes.py

@@ -392,6 +392,22 @@ def __repr__(self):
 
         return repr_str
 
+    def _repr_mimebundle_(self, include, exclude, **kwargs):
+        """
+        repr_mimebundle should accept include, exclude and **kwargs
+        """
+        import plotly.io as pio
+        if pio.renderers.render_on_display:
+            data = pio.renderers._build_mime_bundle(self.to_dict())
+
+            if include:
+                data = {k: v for (k, v) in data.items() if k in include}
+            if exclude:
+                data = {k: v for (k, v) in data.items() if k not in exclude}
+            return data
+        else:
+            return None
+
     def update(self, dict1=None, **kwargs):
         """
         Update the properties of the figure with a dict and/or with

Diff for: plotly/io/__init__.py

@@ -4,3 +4,9 @@
 from ._json import to_json, from_json, read_json, write_json
 
 from ._templates import templates, to_templated
+
+from ._renderers import renderers, show
+
+from . import base_renderers
+
+from ._html import to_html, write_html