PyBc/AdvancedPython: PyBC_S9_simple_num.py

class SimpleNum():
        "A Simple Number in a Simple Metric Space."
        def __init__(self, x):
                if int(x) == 0:
                        self.val = 0
                else:
                        self.val = 1

        def __str__(self):
                return str(self.val)

        def __int__(self):
                return int(self.val)

        def __float__(self):
                return float(self.val)

        def __add__(self, y):
                if self.val == 1:
                        return SimpleNum(1)
                elif int(y) == 0:
                        return SimpleNum(0)
                else: 
                        return SimpleNum(1)
                        
        #__add__() could be more concisely written as:
        #def __add__(self, y):
        #       return SimpleNum(self.val + SimpleNum(y).val)
        #where __init__() takes care of the details...

        def __radd__(self, y):
                "Addition is communative! Here, at least..."
                return self.__add__(y)

        def __sub__(self, y):
                y = SimpleNum(y)
                return SimpleNum(self.val - y.val)

        def __rsub__(self, y):
                "Since we have no negative numbers, subtraction is also communative!"
                return self.__sub__(self, y)

        def __mul__(self, y):
                y = SimpleNum(y)
                return SimpleNum(self.val * y.val)

        def __rmul__(self, y):
                if isinstance(y, SimpleNum):
                        return self.__mul__(y)
                else:
                        return NotImplemented

#Define some SimpleNums
i = SimpleNum(0)
j = SimpleNum(37.0)
k = SimpleNum(True)

print("i = {0}".format(i)) 
print("j = {0}".format(j)) 
print("k = {0}".format(k)) 
print("")

#Define SimpleNums from additive operations 
a = i + 0
b = 0 + j
c = a + b

print("a = {0}".format(a)) 
print("b = {0}".format(b)) 
print("c = {0}".format(c)) 
print("")

#Define SimpleNums from subtraction
p = a - b
q = k - (c + 1) 
r = k - (c - 1) 

print("p = {0}".format(p)) 
print("q = {0}".format(q)) 
print("r = {0}".format(r)) 
print("")

#Define SimpleNums from multiplication
e = j * b
f = q * True
g = c * 3
print("e = {0}".format(e)) 
print("f = {0}".format(f)) 
print("g = {0}".format(g)) 
print("")

h = 50.0 * k
print("h = {0}".format(h))