The version of python which I am using is 2.6, and there is a 2.7 and 3.x. Usually I use python for some trivial program/snippet. I realize there are some major difference between 2.x and 3.x. I would really like to know, if I am going to make a bigger project with python, which version of python should I use?

Should I upgrade to 2.7, or go to 3.x or stay with 2.6?

The decision should be based on these terms:

1. Number of user in the internet as a community. More users mean more open-source package and help from them.

2. Functionality.

3. Support from official development team.

4. Compatibility for existing module/package.

Thanks!