DeprecationWarning with traitlets when using %matplotlib widget

Open

#236 opened on Jun 16, 2020 1 comment 4 reactions 0 assignees View on GitHub

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Assessment

Difficulty: 3/5
Estimated time: 1-2 days
Newbie friendliness: 35/100

Issue type: Bug
Clarity: Mostly clear
Activity status: Stale
Tech stack: jupyter-notebook, python
Domain: frontend

Research direction

Start by reproducing the warning with the supplied Python snippet and the %matplotlib widget backend, then trace the Canvas and Toolbar initialization mentioned in the traceback. Compare behavior with the listed ipympl, ipywidgets, and traitlets versions; done means the example no longer emits these DeprecationWarning messages and the behavior is covered by an appropriate regression check.

Written by the indexing model from the issue text.

Description

Describe the issue

It seems that the widget backend is doing something that is deprecated, and I thought I should make a note of it here.
Example:

import warnings
import matplotlib.pyplot as plt

%matplotlib widget
warnings.simplefilter("always", DeprecationWarning) 
plt.subplots()

I get the following warnings

/home/maij/.local/lib/python3.6/site-packages/ipywidgets/widgets/widget.py:412: DeprecationWarning: Passing unrecoginized arguments to super(Canvas).__init__().
__init__() missing 1 required positional argument: 'figure'
This is deprecated in traitlets 4.2.This error will be raised in a future release of traitlets.
  super(Widget, self).__init__(**kwargs)
/home/maij/.local/lib/python3.6/site-packages/ipywidgets/widgets/widget.py:412: DeprecationWarning: Passing unrecoginized arguments to super(Toolbar).__init__().
__init__() missing 1 required positional argument: 'canvas'
This is deprecated in traitlets 4.2.This error will be raised in a future release of traitlets.
  super(Widget, self).__init__(**kwargs)

Versions

 3.6.9 (default, Apr 18 2020, 01:56:04) 
[GCC 8.4.0]
ipympl version: 0.5.6
jupyter core     : 4.6.3
jupyter-notebook : 6.0.3
qtconsole        : 4.7.4
ipython          : 7.13.0
ipykernel        : 5.2.0
jupyter client   : 6.1.3
jupyter lab      : 2.1.4
nbconvert        : 6.0.0a0
ipywidgets       : 7.5.1
nbformat         : 5.0.4
traitlets        : 4.3.3
JupyterLab v2.1.4
Known labextensions:
   app dir: /usr/local/share/jupyter/lab
        @jupyter-widgets/jupyterlab-manager v2.0.0  enabled  OK
        @jupyter-widgets/jupyterlab-sidecar v0.5.0  enabled  OK
        jupyter-matplotlib v0.7.2  enabled  OK
        shared_kernel v0.1.0  enabled  OK

Dominant language: Jupyter Notebook
Stars: 1.7k
Forks: 234
PR merge metrics: No merged PRs in 30d

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