Rectangles

import pygame, sys, random
from pygame.locals import *

def doRectsOverlap(rect1, rect2):
    for a, b in [(rect1, rect2)]:
        # Check if a's corners are inside b
        if ((isPointInsideRect(a.left, a.top, b)) or
            (isPointInsideRect(a.left, a.bottom, b)) or
            (isPointInsideRect(a.right, a.top, b)) or
            (isPointInsideRect(a.right, a.bottom, b))):
            return True

    return False

def isPointInsideRect(x, y, rect):
    if (x > rect.left) and (x < rect.right) and (y > rect.top) and (y < rect.bottom):
        return True
    else:
        return False

# set up pygame
pygame.init()

# set up the window
WINDOWWIDTH = 600
WINDOWHEIGHT = 600
windowSurface = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT), 0, 32)
pygame.display.set_caption('Rectangles')

# set up the colors
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)

from random import choice
foo = [BLACK, RED, GREEN, BLUE]

# draw the background
windowSurface.fill(WHITE)

print('Please enter a number:')
number = input()
x = 0
array = []
for i in array:

while int(number) > x:
    x = x+1
    x1 = random.randint(1, 400)
    y1 = random.randint(1, 400)
    x2 = random.randint(1, 400)
    y2 = random.randint(1, 400)
    x3 = random.randint(1, 400)
    y3 = random.randint(1, 400)
    x4 = random.randint(1, 400)
    y4 = random.randint(1, 400)
    box = pygame.draw.rect(windowSurface,random.choice(foo), (x1, y1, x2, y2))
    if doRectsOverlap(box, box) == False:
        box
    else:
        x = x-1

# draw the window onto the screen
pygame.display.update()