在要高亮显示的像素位置放置一个矩形。

import matplotlib.pyplot as plt
import numpy as np

def highlight_cell(x,y, ax=None, **kwargs):
    rect = plt.Rectangle((x-.5, y-.5), 1,1, fill=False, **kwargs)
    ax = ax or plt.gca()
    ax.add_patch(rect)
    return rect

img = np.random.rand(4,10)
plt.imshow(img, cmap='Reds')

highlight_cell(2,1, color="limegreen", linewidth=3)

plt.show()