OT: I know that Django 1.6+ can be used with Python 3.4 but is Django 1.7.1 written in Python 2.7 or 3.4?
It is possible, and not too difficult in fact, to write a single codebase that runs under both Python 2 and Python 3. Which is what Django has done. The same code runs the same under 2.7 or 3.3 or 3.4.