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

Isn't this called a function? This may sound like a simple answer, but I mean it sincerely.

def y(x):
    return 2 * (x + 2) ** 2 - 8

Aren't you thinking in the wrong direction with this one?

To address the clarification:

class MyParams():
    distance = 0.0
    speed = 0.0
    def __call__(self):
        return self.distance / self.speed

p = MyParams()
p.distance = 13.4            # These are properties
p.speed = 3.14               # where __get__ returns MagicNumber instances
time = p()  # 4.26
p.speed = 2.28
time = p()  # 5.88

I guess I'm more in favor of this type of a solution, although I see the benefit in the sympy module. Preference, I guess.