text: import matplotlib.pyplot as plt
  import numpy as np
  
  nbPoints = 500
  x = np.random.standard_normal(nbPoints)
  y = np.random.standard_normal(nbPoints)
  
  # 固定种子
  np.random.seed(19680801)
  colors = np.random.rand(nbPoints)
  
  area = (10 * np.random.rand(nbPoints)) ** 2
  
  plt.scatter(x, y, s=area, c=colors, alpha=0.5)
  plt.show()
  