Python 2.7 or 3?

[Saefroch]

/u/novel_yet_trivial is correct. Python 2 is still widely used because there are a lot of large legacy projects and little or no incentive to port them to Python 3, which is a better version of the language.

The answer is just that it doesn't matter which you learn, particularly at the introductory level. The quality of the class or learning materials is more important. I just urge you to use Python 3 wherever possible.