Change Line Colour with Plotly Express

Question

I have a plotly express figure:

fig = px.line(data, x="DateTime", y="Gold", title="Gold Prices")

I want to change some details, like so

fig.update_layout(
    line_color="#0000ff",  # ValueError: Invalid property specified for object of type plotly.graph_objs.Layout: 'line'
    line=dict(
        color='rgb(204, 204, 204)',
        width=5
    ),  # Bad property path: line
)

But both attempts (trying solutions I researched on here) failed, with the errors given in the comments.

I have also tried fig = px.line(data, x="DateTime", y="Gold", title="Gold Prices", template="ggplot2", color_discrete_map={"Gold": "green"}) to no avail.

How do I make this work please?

Sublet

Answer 1

Try to use .update_traces() with plotly.express instead of .update_layout():

fig.update_traces(line_color='#0000ff', line_width=5)

Nashville

Does this work when there are multiple lines please? If so, how to set them? – Sublet

Works for multiple lines but than all lines seem to have the same color, wouldn't take a color list as an input (I had just one line, but a row split). Used the indexing system from r-beginners below. – Ursas

Answer 2

plotly.express

If you want to use plotly.express, add the following settings.

import plotly.express as px

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

fig['data'][0]['line']['color']='rgb(204, 204, 204)'
fig['data'][0]['line']['width']=5

fig.show()

plotly.graph_objects

If you are using plotly.graph_objects, you can set it in go.Scatter().

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

df = px.data.stocks()
fig = go.Figure(data=go.Scatter(x=df['date'], y=df['GOOG'], mode='lines', line_color='rgb(204, 204, 204)', line_width=5))
fig.update_layout(title='Ticker:GOOG')

fig.show()

Sublease

The output of each is the same, so they are one and the same. – Sublease

Answer 3

fig = px.line(data, x="DateTime", y="Gold", title="Gold Prices", color_discrete_map={"DateTime": "blue", "Gold": "green"})

Hyperaemia

Remember that Stack Overflow isn't just intended to solve the immediate problem, but also to help future readers find solutions to similar problems, which requires understanding the underlying code. This is especially important for members of our community who are beginners, and not familiar with the syntax. Given that, can you edit your answer to include an explanation of what you're doing and why you believe it is the best approach? – Biblio

Answer 4

Have you tried simply.

fig.add_scattergl(x=xs, y=df.y, line={'color': 'black'})

Source

Calv

Answer 5

Try using the "set_color" function like so:

fig.set_color('b')

or

fig.set_color('g')

where g and b can also be r for the RGB color scheme. then fig.show()

Levenson

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center. – Annunciator

Doesn't work for me: AttributeError: 'Figure' object has no attribute 'set_color' – Sublet

Answer 6

This worked for me quite well:

fig = px.line(
    data, 
    x="DateTime", 
    y="Gold", 
    title="Gold Prices",
    color_discrete_sequence=["rgb(204, 204, 204)"] # This parameter do the trick.
)

It also works in using something like: color_discrete_sequence=["black"]

Unblown