Say Django 1.11, a massive amount of .py files, works completely fine under both 2 and 3. As do many other libraries.
Yes you often need some precautions like "from __future__ import" statements and sometimes libraries like `six`, but it's been perfectly normal practice for most of the last decade.
Yes you often need some precautions like "from __future__ import" statements and sometimes libraries like `six`, but it's been perfectly normal practice for most of the last decade.