matplotlib: hide subplot and fill space with other subplots

Question

I\'ve got a figure that contains three subplots which are arranged vertically. Once I click into the figure, I want the second subplot ax2 to be hidden and the

Answer 1

You can define two different GridSpecs. One would have 3 subplots, the other 2. Depending on the visibility of the middle axes, you change the position of the other two axes to obey to the first or second GridSpec.
(There is no need for any dummy figure or so, like other answers might suggest.)

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec

fig = plt.figure()

gs = gridspec.GridSpec(3, 1, height_ratios=[5, 2, 1], hspace=0.3)
gs2 = gridspec.GridSpec(2,1, height_ratios=[5,3])

ax1 = fig.add_subplot(gs[0])
ax2 = fig.add_subplot(gs[1], sharex=ax1)
ax3 = fig.add_subplot(gs[2], sharex=ax2)

ax1.plot([1,2,3], [1,2,3], color="crimson")
ax2.plot([1,2,3], [2,3,1], color="darkorange")
ax3.plot([1,2,3], [3,2,1], color="limegreen")

visible = True

def toggle_ax2(event):
    global visible
    visible = not visible
    ax2.set_visible(visible)
    if visible:
        ax1.set_position(gs[0].get_position(fig))
        ax3.set_position(gs[2].get_position(fig))
    else:
        ax1.set_position(gs2[0].get_position(fig))
        ax3.set_position(gs2[1].get_position(fig))

    plt.draw()

fig.canvas.mpl_connect('button_press_event', toggle_ax2)
plt.show()

Left: original; right: after clicking