Yes and No. If you ignore Python being a powerhouse in the scripting world and just focus on numerical stuff like matrix and symbolic math, both Python and Mathematica have that. Some people like myself that love Python and know how to use it and Numpy bought Mathematica licenses. I still use Python for scripting, but I've moved most exploratory work to Mathematica. I miss Python's Spyder IDE, but with Mathematica I can enter equations into Notebooks much more elegantly than having to do OO code which looks significantly different than the math.