Scipy is for numerical computation. It's not a CAS.
While Sympy (which is one of the OSS libraries used in Mathics) is a CAS, it only implements a subset of the features of Mathematica, and not to the same standard. See here: https://news.ycombinator.com/item?id=33478881
While Sympy (which is one of the OSS libraries used in Mathics) is a CAS, it only implements a subset of the features of Mathematica, and not to the same standard. See here: https://news.ycombinator.com/item?id=33478881