Trying to generate an image where each pixel is a random color in python

I'm trying to make an image with a random color for each pixel then print open a window to see the image.

import PIL, random
import matplotlib.pyplot as plt # single use of plt is commented out
import os.path  
import PIL.ImageDraw            
from PIL import Image, ImageDraw, ImageFilter


im = Image.new("RGB", (300,300))

for r in range(0,300):
    for c in range(0,300):
        re = random.randint(0, 255)
        gr = random.randint(0, 255)
        bl = random.randint(0, 255)
        im[r][c]=[re,gr,bl]
im.show()

     14         bl = random.randint(0, 255)
---> 15         im[r][c]=[re,gr,bl]
     16 im.show()
TypeError: 'Image' object does not support indexing