snake game

import pygame
import random

pygame.init()

color = {
    'white': (255, 255, 255),
    'red': (255, 0, 0),
    'green': (0, 255, 0),
    'blue': (0, 0, 255),
    'black': (0, 0, 0)
}

clock = pygame.time.Clock()

screen_width = 600
screen_height = 400

gameDisplay = pygame.display.set_mode((screen_width, screen_height))

block_size = 20

font = pygame.font.SysFont(None, 25)

def message_to_screen(msg, color):
    screen_text = font.render(msg, True, color)
    font_width,font_height = font.size(msg)
    gameDisplay.blit(screen_text, [(screen_width/2) - (font_width/2), (screen_height/2)-(font_height/2)])


def gameLoop():
    gameExit = False
    gameOver = False
    gamePause = False

    lead_x = screen_width/2
    lead_y = screen_height/2

    lead_x_change = 0
    lead_y_change = 0

    randAppleX = random.randrange(block_size, screen_width-block_size, block_size)
    randAppleY = random.randrange(block_size, screen_height-block_size, block_size)

    resume = False

    while not gameExit:

       while gamePause == True:
           if resume == True:
               gamePause = False
               resume = False
               print("sup")
               break
           message_to_screen("Your game has been paused, press p to resume", color['blue'])
           pygame.display.update()
           for event in pygame.event.get():
             if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_p:
                   resume = True
             if event.type == pygame.QUIT:
                 gameExit = True
                 resume = True

       while gameOver == True:

            gameDisplay.fill(color['red'])
            message_to_screen("You have lost, press C to play again or Q to quit", color['blue'])
            pygame.display.update()

            for event in pygame.event.get():
                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_q:
                        gameExit = True
                        gameOver = False
                    elif event.key == pygame.K_c:
                        gameLoop()
                if event.type == pygame.QUIT:
                    gameExit = True


       if gameExit == True:
           break

       for event in pygame.event.get():

            if event.type == pygame.QUIT:
                gameExit = True

            if event.type == pygame.KEYDOWN:

                if event.key == pygame.K_RIGHT or event.key == pygame.K_d:
                    lead_y_change = 0
                    lead_x_change = block_size

                elif event.key == pygame.K_LEFT or event.key == pygame.K_a:
                    lead_y_change = 0
                    lead_x_change = -block_size

                elif event.key == pygame.K_UP or event.key == pygame.K_w:
                    lead_x_change = 0
                    lead_y_change = -block_size

                elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
                    lead_x_change = 0
                    lead_y_change = block_size

                elif event.key == pygame.K_p:
                    gamePause = True

       lead_x += lead_x_change
       lead_y += lead_y_change

       if lead_x + block_size >= screen_width or lead_x <= 0 or lead_y + block_size >= screen_height or lead_y <= 0:

          gameOver = True

       if lead_x == randAppleX and lead_y == randAppleY:

          randAppleX = random.randrange(block_size, screen_width-block_size, block_size)
          randAppleY = random.randrange(block_size, screen_height-block_size, block_size)

       pygame.display.set_caption('gameDev')
       gameDisplay.fill(color['white'])
       gameDisplay.fill(color['green'], rect=[randAppleX, randAppleY, block_size, block_size])
       gameDisplay.fill(color['red'], rect=[lead_x, lead_y, block_size, block_size])
       pygame.display.update()

       clock.tick(6)

gameLoop()
pygame.quit()
quit()