If all the libraries you need are already available for Python 3, then use Python 3. Otherwise, fall back to the 2.x series. Be practical. Evaluate your own nee

If all the libraries you need are already available for Python 3, then use Python 3. Otherwise, fall back to the 2.x series. Be practical. Evaluate your own needs before you listen to somebody else. The 2.x branch is here to stay for quite a long time (I'm guessing 2 to 5 years). <BEGIN RAMBLING> If the users don't drive the library authors/maintainers to make their code compatible with Python 3, then we'll have to wait a very very long time for the 2.x branch to go away. I'm not saying Python 2.x is bad in any way. It just takes too much effort to maintain separate codebases for separate versions of the language. Also, I'm sure the language developers could do something much more useful with their time if they focussed on one version of the CPython implementation. <END RAMBLING>