For this project, I'll be using Python 3.6, which, at the time of writing, is the latest stable release of Python. I recommend always using the latest stable version of Python, not only for the new features but to also ensure the latest security updates are applied to your environment at all times.
I also strongly recommend using virtualenv to create an isolated environment to install our Python requirements. Installing Python requirements without a virtual environment can cause unexpected side-effects with other Python applications, or worse, your operating system!