python matplotlib每第N个小节显示不同的颜色

Question

So i created the following matplotlib diagramm.This is what it looks atm:

Is there any way to change the colors after every 5th bar? Like bar 1-5 have same color, 6-10 have same color, .... Couldn't seem to find the answer. Cheers

Answer 1

Yes, there is, and it's pretty easy. Look at the following code:

from matplot import pyplot as plt
bars = plt.bars(xrange(20), xrange(20))
for item in bars[::5]:
    item.set_color('r')
plt.show()

The bars() method returns a list of objects, where you can set the color with the set_color() method. You then take the list and iterate over it with a step width of 5. You can shift the position of the colored bars by passing a starting index, for example bars[2::5].

This gives the following result:

Edit: To achieve that the color changes on every 5th bar, the code has to look like this:

from matplotlib import pyplot as plt
colors = ['r']*5 + ['b']*5 + ['g']*5
barlist = plt.bar(xrange(15), xrange(15))
for item, color in zip(barlist, colors):
     item.set_color(color)
plt.show()

Which gives:

Answer 2

You can set the color of the bars by supplying a list of colors to the bar plot.

import matplotlib.pyplot as plt
import numpy as np

#generate some data
x = range(24)
y = np.abs(np.random.normal(2, 1, 24))

#generate color list. 
color = ["orange"]*5 + ["purple"]*5 + ["darkturquoise"]*5+ ["firebrick"]*5 + ["limegreen"]*4 
plt.bar(x,y, color = color, align="center")   

plt.xlim((-1,24))
plt.show()