Two or three colorbars for one plot in Plotly

Nice to see more sansanos using plotly, there is an attribute inside marker's colorbar for this purpose, trace.marker.colorbar.x, it requires a value that ranges from -2 to 3, with 0 being the left limit of the plot and 1 being the right limit, you'll usually have to get it by trial and error.

Remember that it's always usefull to provide a sample of your code, so we can provide corrections that follow the paradigm you're working on. Here's an example

from plotly import graph_objects as go

data_x = [1, 2, 3, 4, 5, 6]
data_y = [1, 4, 9, 16, 25, 36]

figure = go.FigureWidget()

# First
first_scatter = go.Scattergl()

first_scatter.mode = 'markers'
first_scatter.x = data_x
first_scatter.y = data_y

first_scatter.marker.colorscale = 'Viridis'
first_scatter.marker.color = data_y
first_scatter.marker.size = 20
first_scatter.marker.showscale = True

first_scatter.showlegend = False
figure.add_trace(first_scatter)

# Second
second_scatter = go.Scattergl()

second_scatter.mode = 'markers'
second_scatter.x = data_x
second_scatter.y = data_y[::-1]

second_scatter.marker.colorscale = 'Electric'
second_scatter.marker.color = data_y
second_scatter.marker.size = 20
second_scatter.marker.showscale = True
second_scatter.marker.colorbar.x = 1.15 # Here

second_scatter.showlegend = False
figure.add_trace(second_scatter)

To access the layout of the plotly. It is handy to override the attribute of the plot through fig.layout

For moving colorbar purpose: In order to separate the 2 colorbars, after creating the first trace/figure, we can access its current reference position and override with new_value before adding another trace

fig.layout.coloraxis.colorbar.x = 1.5 => this will move the bar to the right (default is 1)

fig.layout.coloraxis.colorbar.x = -0.5 => this will move the bar to the left

the same idea will also apply to y value as well as colorscale.

For friendlier using purpose, you can use update method instead:

fig.update_coloraxes(colorbar_x=<VALUE>)

For further detail, you can check out here

Here is an example, where I change the colorbar and its color reference.

#creating a figure and add the first trace

fig = px.density_contour(df[(df["label"]=='capture')&(df["bie"]=='bie')], x="x", y="y") 

# change reference params

fig.layout.coloraxis.colorbar.x = 1.1
fig.update_coloraxes(colorscale="YlGnBu")
fig.update_traces(contours_coloring="fill")

# add new traces with new params

fig.add_traces(
    list(px.scatter(df[df["label"]=='capture'], x="x", y="y",color="state", opacity=0.8).select_traces()))
fig.update_layout(width=1000,height=500,legend=dict(
    yanchor="bottom"))
fig.show()