express plots with "categories" in legend

[K0ertis]

Hi!

I plot pandas dataframe with a "lot" of data

fig = px.line(df,
                x='time [s]',
                y="data [V]",
                line_group="group",
                color='pixel',
                line_dash='group',
                facet_col="int_times [µs]",
                facet_row="gain [1]"
                )

group has 4 elements and pixel has 64 elements which results to a legend which has 256 entries. Would it be possible to just add the type of the legend, like

• pixel [1:64] -> 64 colors
• line _group [1:4]
  dash -> group0
  dot -> group1
  dash-> group2
  longdash->group3

So in total there are 68 elements instead of 256, and each data is accessible by clicking to the right pixel/linestyle

[nicolaskruchten]

This is a good idea which will be implemented once plotly/plotly.js#5099 is implemented, so I'll close as duplicate for now.