I have a loop which loads and plots some data, something like this:

import os
import numpy as np
import matplotlib.pyplot as pltfor filename in filenames:plt.figure()if os.path.exists(filename):x, y = np.loadtxt(filename, unpack=True)plt.plot(x, y)plt.savefig(filename + '.png')plt.close()

Now, if the file does not exist, the data is not loaded or plotted but an (empty) figure is still saved. In the above example I could correct for this simply by including all of the plt calls inside of the if statement. My real use case is somewhat more involved, and so I am in search for a way to ask matplotlib/plt/the figure/the axis whether or not the figure/axis is completely empty or not. Something like

for filename in filenames:plt.figure()if os.path.exists(filename):x, y = np.loadtxt(filename, unpack=True)plt.plot(x, y)if not plt.figure_empty():  # <-- new lineplt.savefig(filename + '.png')plt.close()

To check if an ax has data drawn using plot():

if ax.lines:

If they were drawn using scatter() instead:

if ax.collections: