ValueError: Invalid property specified for object of type plotly.graph_objs.layout.Shape: 'symbol'

[apalkanau]

Reproducible example:

import matplotlib.pyplot as plt
from plotly import tools

fig, ax = plt.subplots()
ax.plot([0, 1], [0, 1], "s-", label="foo")
ax.legend()

tools.mpl_to_plotly(fig)

Works fine without legend or explicit fmt.

This issue is quite severe because it disallows to use some sklearn visualizations:

from sklearn.calibration import CalibrationDisplay
from plotly import tools

display = CalibrationDisplay.from_predictions([1], [0.9])

tools.mpl_to_plotly(display.figure_)

[apalkanau]

Cannot reproduce the same error with the latest version of matplotlib, but receiving

ValueError: Invalid value of type 'builtins.str' received for the 'dash' property of layout.shape.line Received value: '1.5px,2.4749999999999996px'

The 'dash' property is a string and must be specified as:
  - One of the following strings:
        ['solid', 'dot', 'dash', 'longdash', 'dashdot',
        'longdashdot']
  - A number that will be converted to a string

instead

I cannot use matplotlib 2.x because it's deprecated and I'm using python 3.8