Vdebug is a vim plugin that lets you debug all kinds of scripts/languages in vim.
It supports these languages:
At work I use it to debug Perl code and I wanted to use it to debug my python code for personal projects.
the key is: pip install komodo-python-dbgp within your virtualenv once that is done it will create the executable pydbgp in your virtualenv. so you can launch in vim vdbug and then in the shell: