Matplotlib.artist.Artist.add_callback() in Python

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
import time

 
def update():
    plt.get_current_fig_manager().canvas.figure.patch.set_facecolor(str(np.random.random()))
    plt.draw()
    print("Draw at time :", time.time())
     
 
def start_animation():
     
    timer = fig.canvas.new_timer(interval = 50)
    timer.add_callback(update)
    timer.start()
 
fig = plt.figure()
start_animation()
       
fig.suptitle('matplotlib.artist.Artist.add_callback() \
function Example', fontweight ="bold") 

plt.show()

# Implementation of matplotlib function  
from random import randint, choice 
import time 
import matplotlib.pyplot as plt 
import matplotlib.patches as mpatches 
   
   
back_color = "black"
colors = ['red', 'green', 'blue', 'purple'] 
width, height = 4, 4
   
fig = plt.figure() 
plt.xlim([0, width])
plt.ylim([0, height]) 
   
fig.canvas.draw() 
   
def update(): 
    x = randint(0, width - 1) 
    y = randint(0, height - 1) 
   
    arti = mpatches.Rectangle( 
        (x, y), 1, 1, 
        facecolor = choice(colors), 
        edgecolor = back_color 
    ) 
    fig.add_artist(arti)
    fig.draw_artist(arti)
    fig.canvas.blit(fig.bbox) 
    print("Draw at time :", time.time()) 
   
timer = fig.canvas.new_timer(interval = 1) 
timer.add_callback(update) 
timer.start() 
       
fig.suptitle('matplotlib.artist.Artist.add_callback() \
function Example', fontweight ="bold") 

plt.show()