Why should I care?

Despite my personal opinion on Python 2 compatibility that I exposed earlier in this chapter, it is impossible to simply forget about it at this time. There are still some useful packages that are really worth using, but are not likely to be ported in the very near future.

Also, sometimes, we may be constrained by the organization we work in. The existing legacy code may be so complex that porting it is not economically feasible. So, even if we decide to move on and live only in the Python 3 world from now on, it will be impossible to live completely without Python 2 for some time.

Nowadays, it is very hard to call yourself a professional developer without giving something back to the community. So, helping the open source developers add Python 3 compatibility to the existing packages is a good way to pay off the moral debt incurred by using them. This, of course, cannot be done without knowing the differences between Python 2 and Python 3. By the way, this is also a great exercise for those new to Python 3.