Plotly: Is it possible to color specific portion of the line in line chart?

Question

Sample line chart

import plotly.express as px

df = px.data.stocks()
fig = px.line(df, x='date', y="GOOG")
fig.show()

I want to color the values > 1.1 and values<0.95 to a different color(ex: red)

Is it possible in plotly to color the specific portion of the line into a different color?

Answer 1

• you can add a additional traces that are data points outside desired range
• note pandas techniques to ensure that all data points exist for additional trace (use of outer-join to get NaN for points within range)

import plotly.express as px

df = px.data.stocks()
fig = px.line(df, x="date", y="GOOG").add_traces(
    px.line(
        df.loc[~df["GOOG"].between(0.95, 1.1)].merge(
            df, on="date", how="right", suffixes=("", "_r")
        ),
        x="date",
        y="GOOG",
    )
    .update_traces(line_color="red")
    .data
)

fig.show()