prefix is a command line prefix calculator written in python. It supports basic math functions (add, subtract, multiply, divide) as well as some more advanced (exponents, logarithms, etc.)
cl-calc aims to be a simple command line calculator. It can handle precedence unlike a lot of graphical calculators. cl-calc is written in Python and requires PLY (Python-Lex-Yacc).
Traditional but powerful cross-platform calculator. It is written in python and it uses wxWidgets as GUI (project is developed with Boa Constructor). By use of SciPy the vaCalculator can solve linear systems, do math with polynomials, integration etc.
REPCAL (REverse Polish CALculator) is a light and fast calculator in RPN (reverse polish notation) mode for the console (command line). It is written in 180 lines of Python code, and can be used both interactively or inside shell scripts.