If you can do exactly what you want with Python 3.x, great! There are a few minor downsides, such as slightly worse library support1 and the fact that most current Linux distributions and Macs are still using 2.x as default, but as a language Python 3.x is definitely ready. As long as Python 3.x is installed on your user's computers (which ought to be easy, since many people reading this may only be developing something for themselves or an environment they control) and you're writing things where you know none of the Python 2.x modules are needed, it is an excellent choice. Also, most linux distributions have Python 3.x already installed, and all have it available for end-users. Some are phasing out Python 2 as preinstalled default.2