Monte Carlo - Pi - Python

import random

def withinCircle(x,y):
    if(x**2+y**2<1):
        return True
    else:
        return False

def main():
    circleArea = 0.0
    squareArea = 0.0
    math = 3.14159
    pi = 0.0
    for i in range(0,100000):
        x = random.random()
        y = random.random()
        if withinCircle(x,y):
            circleArea=circleArea+1
        squareArea=squareArea+1
    pi = 4*circleArea/squareArea
    print "Approximate value for pi: ", pi
    print "Difference to exact value of pi: ", pi-math
    print "Error: (approx-exact)/exact=", (pi-math)/math*100, "%"

if __name__ == "__main__":
    main()