I would rather use plt.clf() after every plt.show() to just clear the current figure instead of closing and reopening it, keeping the window size and giving you a better performance and much better memory usage.
Similarly, you could do plt.cla() to just clear the current axes.
To clear a specific axes, useful when you have multiple axes within one figure, you could do for example:
fig, axes = plt.subplots(nrows=2, ncols=2)
axes[0, 1].clear()