If you want to master, or even just use, data analysis, Python is the place to do it. Python is easy to learn, it has vast and deep support, and most every data science library and machine learning framework out there has a Python interface.
Over the past few months, several data science projects for Python have released new versions with major feature updates. Some are about actual number-crunching; others make it easier for Pythonistas to write fast code optimized for those jobs.