How to resize legend items

[ismirsehregal]

You could use the layout attributes itemsizing and itemwidth:

import plotly.graph_objects as go

dict_of_fig = dict({
    "data": [{"type": "scatter",
              "x": [1, 2, 3],
              "y": [1, 3, 2]}],
    "layout": {"legend": {"itemsizing": "constant", "itemwidth": 100}}
})

fig = go.Figure(dict_of_fig)
fig.add_trace(go.Scatter(x=[1, 2, 3], y=[2, 3, 4]))
fig.show()