How to create minor ticks for polar plot matplotlib

Question

I am interested in the following two things for the polar plot plotted by matplotlib shown below

1. How do I create minor ticks for a polar plot on the r axis?
2. How do I move the r labels further away from the r ticks, as seen in the graph, some of the r ticks are in contact with the axis.

Answer 1

The polar plot does not have minor or major ticks. So I think you need to create the minor ticks manually by plotting small line segments.

For example:

import numpy as np
import matplotlib.pyplot as plt

r = np.arange(0, 2, 0.01)
theta = 2 * np.pi * r

ax = plt.subplot(111, projection='polar')
ax.plot(theta, r)
ax.set_rmax(2)
ax.margins(y=0)
ax.set_rticks([0.5, 1, 1.5, 2])  # less radial ticks
ax.set_rlabel_position(120)  # get radial labels away from plotted line

ax.grid(True)

tick = [ax.get_rmax(),ax.get_rmax()*0.97]
for t  in np.deg2rad(np.arange(0,360,5)):
    ax.plot([t,t], tick, lw=0.72, color="k")

ax.set_title("A line plot on a polar axis", va='bottom')
plt.show()