Comment 2 for bug 1577787

Hi,
cloud-init has no dependency on python. It is possible that your user-scripts do, but that is beyond the control of cloud-init. The ubuntu 16.04 cloud images do not have a python2 interpreter installed.

I put together a gist on how to run either python2 or python3 based on what is available at https://gist.github.com/smoser/8904199bb8f00a90dd04 that might be useful. The key point though, is that 16.04 images do not have python installed. If you need it, install python2 with apt.