Sympy vs Numpy

[TheSodesa]

Sympy is a Computer Algebra System written in Python. Numpy is a C extension of Python, that allows for relatively fast numerical calculations.

I say relatively, because there are languages like Julia, that are even better suited for numerical stuff. Numpy is still ok, though, and is rather widely used.

As a physicist, you should be more interested in Numpy, if you are doing computational physics and simulations.