How to pick a new color for each plotted line within a figure in matplotlib?

Question

I'd like to NOT specify a color for each plotted line, and have each line get a distinct color. But if I run:

from matplotlib import pyplot as plt
for i in range(20):
    plt.plot([0, 1], [i, i])

plt.show()

then I get this output:

If you look at the image above, you can see that matplotlib attempts to pick colors for each line that are different, but eventually it re-uses colors - the top ten lines use the same colors as the bottom ten. I just want to stop it from repeating already used colors AND/OR feed it a list of colors to use.

Answer 1

I usually use the second one of these:

from matplotlib.pyplot import cm
import numpy as np

#variable n below should be number of curves to plot

#version 1:

color = cm.rainbow(np.linspace(0, 1, n))
for i, c in zip(range(n), color):
   plt.plot(x, y, c=c)

#or version 2:

color = iter(cm.rainbow(np.linspace(0, 1, n)))
for i in range(n):
   c = next(color)
   plt.plot(x, y, c=c)

Example of 2: