Zero-Cost Abstraction

high-cost.py

class Sum(object):
    def __init__(self):
        self._sum = 0

    def increment(self, val):
        self._sum += val

    def print_sum(self):
        print self._sum

s = Sum()

for i in range(1, 1000001):
    s.increment(i)

s.print_sum()

low-cost.py

sum = 0
for i in range(1, 1000001):
    sum += i
print sum