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.

Nell’issue non sono indicati né un file sorgente né un test. Inizia individuando il comportamento di mutazione e ripristino del layout della figura, quindi esamina come un context manager potrebbe preservare i valori esistenti e ripristinarli dopo fig.write_image('plot.pdf'); done dovrebbe includere la copertura per le modifiche temporanee di showlegend senza eliminare le chiavi del layout.