Move Patch Rather Than Remove It

I have a graph that is gradually revealed. Since this should happen with a huge dataset and on several subplots simultaneously, I was planning to move the patch rather than remove

Solution 1:

Maybe this works for you. Instead of removing the patch, you just update its position and its width (with rect.set_x(left_x) and rect.set_width(width)), and then redraw the canvas. Try replacing your loop with this (note that the Rectangle is created once, before the loop):

rect = plt.Rectangle((0, 0), nmax, 1, zorder=10)
ax.add_patch(rect)

for i in range(nmax):
    rect.set_x(i)
    rect.set_width(nmax - i)
    fig.canvas.draw()
    plt.pause(0.1)