Python number-like class that remembers arithmetic operations?

Question

I\'m wondering if there exists a python module that would allow me to do something like this:

x = MagicNumber()
x.value = 3
y = 2 * (x + 2) ** 2 - 8
print y          


        

Answer 1

You could give sympy, a computer algebra system written in Python, give a try.

E.g.

>>> from sympy import Symbol
>>> x = Symbol('x')
>>> y = 2 * (x + 2) ** 2 - 8
>>> y
2*(x + 2)**2 - 8
>>> y.subs(x,3)
42
>>> y.subs(x,2)
24