Plotly: How to set title color for scatter traces when not using plotly express?

Question

When I do a scatter plot like this:

fig2 = go.Figure()

for num in range(len(dy)):
    data = dz[0:,num]
    fig2.add_trace(go.Scatter(x=dx, y=data, name=str(dy[num]), mode='lines'))

How do I set the color coding title, like when doing color= in plotly.express.line?

You're only taking about the color of the traces here, right? And not the *titles* of anything? Or are you talking about the colors of the traces and the color of the names in the legend at the same time? — vestland, Feb 21 '20 at 07:54
@vestland I talk about the title above the legend for the traces. Like for example in you answer below you have px.line(df, x="year", y="lifeExp", color='country') that will place the word 'country' above the legend for the traces. That word is what I am after. — Invariant, Feb 21 '20 at 14:53

vestland · Accepted Answer · 2020-02-25T19:07:07.163

You can edit font color, size and family through fig.update(legend_title=dict(font=dict(color='Blue'))):

Complete code:

import plotly.express as px
import plotly.graph_objects as go

df = px.data.gapminder().query("continent=='Oceania'")

countries = df['country'].unique()
countries

fig2 = go.Figure()
for country in countries:
    df2 = df[df['country']==country]
    fig2.add_traces(go.Scatter(x=df2['year'], y=df2['lifeExp'], name = country,
                              mode='lines',
                              ))

fig2.update_xaxes(title='Year')
fig2.update_yaxes(title='LiefExp')

fig2.update_layout(legend_title=dict(text='Country',
                                     font=dict(family="sans-serif",
                                     size = 18,
                                     color='blue')))


fig2.show()

Plotly: How to set title color for scatter traces when not using plotly express?

1 Answers1