Animation with matplotlib where points are dynamic

I've written a simple code which generates random points (x,y) between certain values using a while loop. After the coordinates of each point are set, that point is drawn in an empty graph which is showed at the end of the while loop.

However, I would like to set up an animation with matplotlib which would allow me to see the initial graph and the points progressively added to it as the code is calculating them. I've looked for some examples but the ones I found are mainly concerned with waves and so on and I guess I need a slightly different approach.

This is the basic code:

from numpy import *
from pylab import *
import random

figure(figsize=(8,6), dpi=150)
x = np.linspace(-1, 4.5, 250)

h=5
a=0.5
b=4

ylim(-0.5,5.5)
xlim(-1,5.0)

i= 0

while i< 500:
    R1 = random.random()
    R2 = random.random()
    x0 = (b - a)*R1 + a
    y0 = h*R2
    scatter(x0, y0, 10, color="red")
    i = i + 1

show()

Thanks for your help!

EDIT:ANIMATION CODE

import numpy as np
import matplotlib.pyplot as plt
from pylab import *
import matplotlib.animation as animation
import random

fig = plt.figure(figsize=(8,6), dpi=150)
x = np.linspace(-2, 4.5, 250)


h=4
a=1
b=3

hlines(y=h, xmin=1, xmax=3, linewidth=1.5)
vlines(x=a, ymin=0, ymax=4, linewidth=1.5)
vlines(x=b, ymin=0, ymax=4, linewidth=1.5)

ylim(-2.5,10.5)
xlim(-2.5,4.5)
grid()

def data_gen():
    i = 0
    while i< 1:
        R1 = random.random()
        R2 = random.random()
        x0 = (b - a)*R1 + a
        y0 = h*R2
        i = i + 1
        yield x0, y0


line, = plot([], [], linestyle='none', marker='o', color='r')

ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.spines['bottom'].set_position(('data',0))
ax.yaxis.set_ticks_position('left')
ax.spines['left'].set_position(('data',0))

xdata, ydata = [], []

def run(data):
    x0,y0 = data
    xdata.append(x0)
    ydata.append(y0)
    line.set_data(xdata, ydata)

    return line,

ani = animation.FuncAnimation(fig, run, data_gen, blit=True, interval=0.5,
    repeat=False)
plt.show()