Debian (and therefore Ubuntu) Python packages are largely intended for system Python, that is, the version of Python that ships with the distro. If you install

Debian (and therefore Ubuntu) Python packages are largely intended for system Python, that is, the version of Python that ships with the distro. If you install a package from a Deb-like repo, its dependencies will be present, and it will work* as intended. The downside is, as you found, they're usually out of date. The upside is that if you get a Python program added to Stable, you can rest easy knowing that end users won't have to battle dependency hell to get it running. *: This does not apply if you've made a FrankenDebian by combining Sid and Stable, or other such things. You're on your own, good luck.