如何删除图形数量不均匀的空matplotlib AxesGrid单元格？

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import ImageGrid

fig = plt.figure()
grid = ImageGrid(fig, 111, nrows_ncols=(2, 3), axes_pad=0.1)
grid[0].imshow(image1)
grid[1].imshow(image2)
grid[3].imshow(image3)

for ax in grid[len(grid) - 1:]:
    ax.remove()

fig.tight_layout()

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import ImageGrid

fig = plt.figure()
grid = ImageGrid(fig, 111, nrows_ncols=(2, 3), axes_pad=0.1)
grid[0].imshow(image1)
grid[1].imshow(image2)
grid[3].imshow(image3)

for ax in grid[len(grid) - 1:]:
    ax.remove()

fig.tight_layout()
plt.show()