calculo de pi

from random import *
for i in range(0,1000):
   x=random()
   y=random()
   plt.plot(x,y,'.b')

for i in range(0,10000):
   x=random()
   y=random()
   r=(x-0.5)*(x-0.5)+(y-0.5)*(y-0.5)
   plt.axis('square')
   if r<=0.25: plt.plot(x,y,'.r')
   if r>0.25:  plt.plot(x,y,'.b')