To start with, what's so great about Python? Why do you want to learn it? There are lots of good answers to those questions. One is that Python is powerful. The Python language is expressive and productive, it comes with a great standard library, and it's the center of a huge universe of wonderful third-party libraries. With Python you can build everything from simple scripts to complex applications, you can do it quickly, you can do it safely, and you can do it with fewer lines of code than you might think possible.
But that's just one part of what makes Python great. Another is that Python is wonderfully open. Its open-source, so you can get to know every aspect of it if you want. At the same time, Python is hugely popular and has a great community to support you when you run into trouble. This combination of openness and large userbase means that almost anyone – from casual programmers to professional software developers – can engage with the language at the level they need.
Another benefit of a large user base is that Python is showing up in more and more places. You may be wanting learn Python simply because it's the language of some technology you want to use, and this is not surprising – many of the most popular web and scientific packages in the world are written in Python.
But for many people those reasons take back-seat to something more important: Python is fun! Python's expressive, readable style, quick edit-and-run development cycle, and "batteries included" philosophy mean that you can sit down and enjoy writing code rather than fighting compilers and thorny syntax. And Python will grow with you. As your
experiments become prototypes and your prototypes become products, Python makes the experience of writing software not just easier but truly enjoyable.
In the words of Randall Munroe, "Come join us! Programming is fun again!"