I had trouble with latest update to "p7", too today. But only on my Laptop, desktop went well. here it was less with py-packages, but with screening the repository and "wayland"-packages, although I don t want Wayland, but keep Xorg!? It first got stuck on reading in repo and that wayland stuff, then, it started "twitching" back and force with the little window with its progess bar and a message like "404 candidates" in brackets, whatever it meant.
After an hour I stopped it via closing update-station and started the command line option: sudo update -f sudo upgrade -f, which re-installed almost everything, but after re-boot the system was updated to "p7", minor some flaws in my personal settings. Would recommend to try the command line option as well like above. Usually it fixes dependency flaws as it looks with You, otherwise there shd be a backup of "BE" to get back to working environment, right?