Estimates the value of PI

my_pi.py

#coding: utf-8
# Estimates the value of PI
# Based on example described at http://code.google.com/edu/parallel/mapreduce-tutorial.html#Basics
# Author: Marcelo Criscuolo (Jaú), with 
# invaluable contributions from Rafael Giusti (Argentino)

import math
from datetime import datetime

RADIUS = 50000 # the bigger the number, more precise is the estimation
SQ_RADIUS = RADIUS ** 2

t0 = datetime.now()
x = RADIUS
y = 0
area_section = 0
while x > 0:
    sq_y = y ** 2
    while (sq_y + (x ** 2)) > SQ_RADIUS:
        x -= 1
    area_section += x
    y += 1
area_circle = 4 * area_section
area_square = (2 * RADIUS) ** 2
pi = 4.0 * area_circle / area_square
t1 = datetime.now()

print pi, '\t\testimated'
print math.pi, '\t\tfrom math.pi'
print abs(pi - math.pi)
print (t1 - t0)

RADIUS = 50000
3.1415924176            estimated
3.14159265359          from math.pi
2.3598979304e-07
0:00:00.110000         time (less than 1sec)