import numpy as np
import matplotlib.pyplot as plt

plt.figure(1)
ax = plt.subplot(111)
x = np.linspace(0, np.pi * 2, 200)  

r = 2 * np.cos(x)  
ax.plot(r * np.cos(x), r * np.sin(x))


r = 1
ax.plot(r * np.cos(x), r * np.sin(x))

plt.show() 
