matplotlib: AttributeError: 'AxesSubplot' object has no attribute 'add_axes'
There's not much details to go on in your question but I'll wager a guess.The error is pretty self-explanatory. You can't add_axes to pyplot_2 because pyplot_2 is a matplotlib.axes.AxesSubplot object and they don't have an add_axes method defined.
Only matplotlib.figure.Figure objects have add_axes method defined on them.
From what I got from a short browse through the WCSAxes official documentation their recommended approach would be:
wcs = astropy.wcs.WCS(....)fig = matplotlib.pyplot.figure()pyplot_2 = fig.add_subplot(gridspec_layout[2], projection=wcs)
You now need to use set_prop_cycle i.e. ax.set_prop_cycle(color=['red', 'green', 'blue'])
Axes.set_color_cycle(clist) was depreciated since, version 1.5.
https://matplotlib.org/3.1.0/api/_as_gen/matplotlib.axes.Axes.set_prop_cycle.html
just downgrade matploblit to an old version would help. I downgrade it to 1.4.0 and it fix the problem.