change context manager for temporary auto-reverted `figure.layout`

Instead of

fig.layout.showlegend = False
fig.write_image('plot.pdf')
fig.layout.showlegend = True

it would be nice to write

from plotly.express import plotly_patch  # or similar

with plotly_patch(fig.layout, showlegend=False):
    fig.write_image('plot.pdf')

I tried

from unittest.mock import patch

with patch.dict(fig.layout, showlegend=False):
    fig.write_image('plot.pdf')

which unfortunately doesn't correctly restore the previous value but tries to delete the patched keys which is undesired behavior and raises AttributeError to boot:

   1906 """Unpatch the dict."""
   1907 if self._original is not None:
-> 1908     self._unpatch_dict()
...
   1934 keys = list(in_dict)
   1935 for key in keys:
-> 1936     del in_dict[key]

AttributeError: __delitem__

Related

Found this forum post where such a context manager was welcomed.

L’issue ne nomme aucun fichier source ni aucun test. Commencez par localiser le comportement de mutation et de restauration du layout de la figure, puis examinez comment un context manager pourrait préserver les valeurs existantes et les restaurer après fig.write_image('plot.pdf'); done devrait inclure une couverture pour les modifications temporaires de showlegend sans supprimer les clés du layout.