text: from mpl_toolkits.mplot3d import Axes3D
  import matplotlib.pyplot as plt
  import numpy as np
  
  fig = plt.figure()
  ax = fig.add_subplot(111, projection='3d')
  
  u = np.linspace(0, 2*np.pi, 100)
  v = np.linspace(0, np.pi, 100)
  
  x = []
  y = []
  z = []
  for phi in u:
      x.append([])
      y.append([])
      z.append([])
      for theta in v:
          x[-1].append(np.sin(theta)*np.cos(phi))
          y[-1].append(np.sin(theta)*np.sin(phi))
          z[-1].append(np.cos(theta))
  
  
  
  
  ax.plot_surface(x, y, z, rstride=4, cstride=4, color='b')
  
  plt.show()
  