Python matplotlib -根据值向网格图添加边框

import matplotlib.pyplot as plt
import matplotlib.colors as colors
from matplotlib.colors import BoundaryNorm

data = [[1, 2, 3],
        [4, 5, 6],
        [7, 8, 9]]

bounds = [0, 3, 6, 9]  # 边框范围

fig, ax = plt.subplots()
cmap = plt.get_cmap('Blues')  # 颜色映射
norm = BoundaryNorm(bounds, cmap.N)  # 边框范围映射

im = ax.imshow(data, cmap=cmap, norm=norm)

# 添加边框
for i in range(len(data)):
    for j in range(len(data[0])):
        text = ax.text(j, i, data[i][j],
                       ha="center", va="center", color="w")

# 添加颜色条
cbar = ax.figure.colorbar(im, ax=ax)

plt.show()