Watch as I learn Python! Or don't. Whatever.
As of the beginning of the year, there are two versions of Python available for Debian:
python, which is at version 2.7.3 (latest available at python.org is 2.7.9), andpython3, which is at version 3.2.3 (latest available at python.org is 3.4.2)
Since I wanted the latest and greatest, I built 3.4.2 from source following these directions (twice, actually, because my fingers typed /user/ when my brain thought /usr/).
I also had to add the new python directory to the PATH environment variable in my .bashrc file, like so: export PATH="$PATH:/usr/local/opt/python-3.4.2/bin".