# 导入 networkx 和 pyplot
  import networkx as nx
  from matplotlib import pyplot as plt

  # 设置图形大小
  plt.rcParams["figure.figsize"] = [7.00, 3.50]
  plt.rcParams["figure.autolayout"] = True

  # 画出图形
  G = nx.grid_2d_graph(3, 3)
  nx.draw(G, node_size=100)

  plt.show()