I'm a physicist, and I use Python (with scipy/numpy when appropriate) when I can get away with it (ie for small to medium-sized calculations). For big calculat

I'm a physicist, and I use Python (with scipy/numpy when appropriate) when I can get away with it (ie for small to medium-sized calculations). For big calculations, though, where what you can do is limited by performance, there's no getting away from C++ or Fortran. Python has a huge performance overhead (I have learned this the hard way).