The Plotly.py functionsfig.add_vline(),fig.add_hline(),fig.add_hrect(),fig.add_vrect() accept arguments such asannotation_text which are used to create a label for the shape. This is done by creating and adding two separate objects to the Plotly.js layout: a shape, and an annotation.

However,now that Plotly.js has added support for shape labels, this is no longer necessary -- the text can be added directly as a label to the shape rather than creating two separate objects.

This would solve issues such as#3065 where we are doing some hacky stuff to get the label in the right place.