forget virtualenv; forget package dependencies on conflicting versions of libxml; forget coworkers that have 3 different conflicting versions of requests scattered through various services, and goddamnit I just want to run a dev build; forget coworkers that scribble droppings all over the filesystem, and assume certain services will never coexist on the same box
just use docker. It's going to go like this:
step 1: docker
step 2: happy