Holoviews: Bokeh 2.0.0 Compatibility

Created on 11 Mar 2020 · 1Comment · Source: holoviz/holoviews

According to the release notes of Bokeh 2.0.0:

bokeh.plotting.helpers Entire module removed

Yet, Holoviews seems to try to use bokeh.plotting.helpers during _load_bokeh (see logs below)

According to, Holoviews 1.12.7 is the latest version on conda-forge. Is Holoviews 1.12.7 incompatible to Bokeh 2.0.0?

ALL software version info

The following packages are installed in my conda environment, from channel conda-forge woth flag --strict

Description of expected behavior and the observed behavior

hv.notebook_extension('bokeh') should not raise an error

Complete, minimal, self-contained example code that reproduces the issue

Create an env in conda:

conda create -n holo_env python=3.7 -c conda-forge
conda activate holo_env
conda config --env --set channel_priority strict
conda config --show channel_priority # verify
conda install -c conda-forge geopandas fiona jupyterlab geoviews holoviews nbconvert descartes numpy mapclassify

Then, in jupyter lab:

import holoviews as hv
hv.notebook_extension('bokeh')

If I revert to the previous revision of the environment (with bokeh=1.4.0), the above does not raise an error, e.g.:

conda install --revision 5 -c conda-forge

.. where 5 is the environment rev number where bokeh=1.4.0. It is the same as if creating the above env with

conda install -c conda-forge geopandas fiona jupyterlab geoviews holoviews nbconvert descartes numpy mapclassify bokeh=1.4.0 -n holo_env

Stack traceback and/or browser JavaScript console output

WARNING:param.notebook_extension: Holoviews bokeh extension could not be imported, it raised the following exception: ModuleNotFoundError('No module named 'bokeh.plotting.helpers'')
WARNING:param.notebook_extension: bokeh backend hook <function _load_bokeh at 0x7f9f63b4f7a0> failed with following exception: No module named 'bokeh.plotting.helpers'
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-1-4d21d4bcd86d> in <module>
     26 import shapely.speedups as speedups
     27 speedups.enable()
---> 28 hv.notebook_extension('bokeh')

~/miniconda3/envs/jupyter_env_strict/lib/python3.7/site-packages/param/parameterized.py in __new__(class_, *args, **params)
   2810         inst = class_.instance()
   2811         inst.param._set_name(class_.__name__)
-> 2812         return inst.__call__(*args,**params)
   2813 
   2814     def __call__(self,*args,**kw):

~/miniconda3/envs/jupyter_env_strict/lib/python3.7/site-packages/holoviews/ipython/__init__.py in __call__(self, *args, **params)
    114 
    115     def __call__(self, *args, **params):
--> 116         super(notebook_extension, self).__call__(*args, **params)
    117         # Abort if IPython not found
    118         try:

~/miniconda3/envs/jupyter_env_strict/lib/python3.7/site-packages/holoviews/util/__init__.py in __call__(self, *args, **params)
    708 
    709         if selected_backend is None:
--> 710             raise ImportError('None of the backends could be imported')
    711         Store.set_current_backend(selected_backend)
    712 

ImportError: None of the backends could be imported