How to extract colors from branca colormap using Python?

Question:

From the below branca colormap

import branca

color_map = branca.colormap.linear.PuRd_09.scale(0, 250)

colormap = color_map.to_step(index=[0, 10, 20, 50, 70, 90, 120, 200])

enter image description here

How can I extract hex colours for all the steps(index) from the above Branca colormap?

Asked By: Ailurophile

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Source

Answers:

The source code on GitHub shows that to_step returns a StepColormap object. This object (line 500 in the linked code) shows that StepColormap has a colors attribute. You should be able to index through the colors that way:

import branca

color_map = branca.colormap.linear.PuRd_09.scale(0, 250)

colormap = color_map.to_step(index=[0, 10, 20, 50, 70, 90, 120, 200])

for color in colormap.colors:
    print(color)
Answered By: SNygard

You can use matplotlib.colors.to_hex on colormap.colors:

from matplotlib.colors import to_hex

out = [to_hex(c) for c in colormap.colors]

# or
out = list(map(to_hex, colormap.colors))

Output:

['#f7f4f9', '#f0ebf4', '#e3d9eb', '#d0aad2', '#d084bf', '#e44199', '#67001f']
Answered By: mozway