I forget who said it, but Python isn't the best at anything but it's decent to good at nearly everything, and that's why it's become so popular.
I do a lot of what I need symbolically in SymPy for dynamics analysis. Past that, I can't speak for it. At University I used Mathematica, but I just don't need all it can do at this point, so once again Python has proven to be "good enough." Matlab will be a similar story (e.g., I've never seen a good alternative to Simulink in Python).
But for everything else outside very specific domain tasks? Mathematica and Matlab are terrible for a lot of reasons. So I'll go out of my way to stay within the Python ecosystem, though I'm not afraid to pull out the specialty tools when I just can't make Python do the task near as well and/or nearly as quickly.
