SymPy is a Python library for symbolic mathematics. It aims to become
a full-featured computer algebra system (CAS) while keeping the
code as simple as possible in order to be comprehensible and easily
extensible. SymPy is written entirely in Python and does not require
any external libraries.

If you install iPython on your machine, sympy could take advantage of it.

Optional dependency (as of version 0.7.1): pyglet, needed only for
plotting.

NOTE: Please read
https://github.com/sympy/sympy/wiki/Release-Notes-for-0.7.0 for backward
compatibility issues with sympy 0.6.x.