There are two major Python versions, Python 2 and Python 3. Python 2 and 3 are quite different. This tutorial uses Python 3, because it more semantically correct and supports newer features.
For example, one difference between Python 2 and 3 is the print statement. In Python 2, the "print" statement is not a function, and therefore it is invoked without parentheses. However, in Python 3, it is a function, and must be invoked with parentheses.
In this video of Python Series you will learn:
A Complete Comparison Between Python 2 and Python 3.