Need help with keeping the squares from leaving the screen. Its supposed to switch direction once it hits a side.

import pygame

import sys

pygame.init$()$

screen$\_$width $=1000$

screen$\_$height $=500$

rect$\_$size $=100$

green $=(0,255,0)$

blue $=(0,0,255)$

move$\_$speed $=5$

screen $=$ pygame.display.set$\_$mode$(($screen$\_$width, screen$\_$height$))$

pygame.display.set$\_$caption$(\text{'}$Lab$7$C: Moving Rects with Surfaces'$)$

clock $=$ pygame.time.Clock$()$

surface$\_$green $=$ pygame.Surface$(($rect$\_$size, rect$\_$size$))$

surface$\_$green.fill$($green$)$

surface$\_$blue $=$ pygame.Surface$(($rect$\_$size, rect$\_$size$))$

surface$\_$blue.fill$($blue$)$

rect$1=$ pygame.Rect$(0,0,$ rect$\_$size, rect$\_$size$)$

rect$2=$ pygame.Rect$(0,$ screen$\_$height $-$ rect$\_$size, rect$\_$size, rect$\_$size$)$

move$\_$right$1=$ True

move$\_$right$2=$ True

running $=$ True

while running:

for event in pygame.event.get$()$:

if event.type $==$ pygame.QUIT:

running $=$ False

elif event.type $==$ pygame.KEYDOWN:

if event.key $==$ pygame.K$\_$ESCAPE:

running $=$ False

if move$\_$right$1$:

rect$1.$x $+=$ move$\_$speed

if rect$1.$x $>$ screen$\_$width:

rect$1.$x $=-$rect$\_$size

else:

rect$1.$x $-=$ move$\_$speed

if rect$1.$x rect$\_$size:

rect$1.$x $=$ screen$\_$width

if move$\_$right$2$:

rect$2.$x $+=$ move$\_$speed

if rect$2.$x $>$ screen$\_$width:

rect$2.$x $=-$rect$\_$size

else:

rect$2.$x $-=$ move$\_$speed

if rect$2.$x rect$\_$size:

rect$2.$x $=$ screen$\_$width

screen.fill$((0,0,0))$

screen.blit$($surface$\_$green, rect$1)$

screen.blit$($surface$\_$blue, rect$2)$

pygame.display.flip$()$

clock.tick$(60)$

pygame.quit$()$

sys$.$exit$()$