I'd suggest Python 3. 

There are mechanisms for managing virtual environments for Python, like penv, which make it easy to install and switch between versions without confusing the system.

-Tod

> On Mar 7, 2018, at 2:14 PM, Eric Lease Morgan <[log in to unmask]> wrote:
> 
> I need some advice regarding writing in Python 2 versus Python 3.
> 
> I have been trying to write more of my software in Python because everybody around me is speaking French (Ruby), Italian (R), or Spanish (Javascript) when I’m speaking in Latin (Perl). My latest example is a set of command-line tools (Bash as well as Python) designed to do scalable reading against HathiTrust content. [1] I originally wrote the tools in Python 2. Since then I learned more about the HathiTrust Research Center “capsules” (on-demand virtual machines), and there Python 3 is the default environment. So, I tweaked my code and it works out-of-the-box and as expected. 
> 
> On the other hand, my kewl tools no longer work in my local environment because I use Python 2, and I don’t feel like installing YAVoP (Yet Another Version of Python) on my server(s). 
> 
> What’d do you suggest? Do you suggest writing in: 1) Python 2 or 2) Python 3 or 3) a combination of both?
> 
> [1] HathiTrust Research Center Workset Browser - https://github.com/ndlib/text-analysis-htrc
> [2] HathiTrust Research Center “capsules” - https://analytics.hathitrust.org/staticcapsules
> 
> —
> Eric Morgan