Plotly add_hline() doesn't work with simple_white template

I was attempting to add a horizontal line to a Plotly graph using Plotly's add_hline(). It works perfectly fine so long as I do not use the simple_white template. The MWE is here:

import plotly.express as px    df = px.data.iris()  fig = px.scatter(df, x="petal_length", y="petal_width")  fig.add_hline(y=0.9, line_dash='dash', line_color='Red')  fig.update_layout(width=400, height=400,                    # template='simple_white'                    )  fig.show()  

Without the template='simple_white' line, the add_hline() works as expected. With that template though, and with no other changes, the plot is the same but without the horizontal line.

https://stackoverflow.com/questions/67327670/plotly-add-hline-doesnt-work-with-simple-white-template April 30, 2021 at 11:03AM