Snake change characters fail

import pygame
import time
import random


pygame.init()


white = (255,250,250)
black = (0,0,0)
red = (255,0,0)
lime_green = (0,200,0)
snakething = (164,120,80)
gray = (124,124,124)
red = (200,0,0)
light_red = (255,0,0)

yellow = (200,200,0)
light_yellow = (255,255,0)

green = (34,177,76)
light_green = (0,255,0)

display_width = 800
display_height = 600


gameDisplay = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption('MLG Snake')



charL = pygame.image.load('goomba left.png')
charR = pygame.image.load('goomba right.png')
charU = pygame.image.load('goomba backward.png')
charD = pygame.image.load('goompa forward.png')
loser = pygame.image.load('game over.png')
imggg = pygame.image.load('introo.png')
yum = pygame.image.load('doritos.png')
cont = pygame.image.load('controls.png')
button_1 = pygame.image.load('button 1.png')
button_2 = pygame.image.load('button 2.png')
button_3 = pygame.image.load('button 3.png')
button_4 = pygame.image.load('button 4.png')



icon = pygame.image.load('doritos.png')
pygame.display.set_icon(icon)




clock = pygame.time.Clock()



block_size = 20

AppleThickness = 30

FPS = 15

direction = "left"

smallfont = pygame.font.Font("D:/Desktop/snake/Pixeled.ttf", 25)

smallmedfont = pygame.font.Font("D:/Desktop/snake/Pixeled.ttf", 38)

medfont = pygame.font.Font("D:/Desktop/snake/Pixeled.ttf", 50)

largefont = pygame.font.Font("D:/Desktop/snake/Pixeled.ttf", 80)

tinyfont = pygame.font.Font("D:/Desktop/snake/Pixeled.ttf", 18)



def pause():
    paused = True
    message_to_screen("Paused", black, -100, "large")
    message_to_screen("Press U to continue or q to quit.", black, 25)
    pygame.display.update()

    while paused:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_u:
                    paused = False

                elif event.key == pygame.K_q:
                    pygame.quit()

                    quit()

        #gameDisplay.fill(gray)

        clock.tick(15)

def score(score):
    text = smallfont.render("Score: "+str(score), True, black)
    gameDisplay.blit(text, [0,-10])

def randAppleGen():
    randAppleX = random.randrange(0, display_width - AppleThickness, 10)
    randAppleY = random.randrange(0, display_height - AppleThickness, 10)

    return randAppleX, randAppleY












def snake(block_size, snakeList):


    if direction == "left":
        gameDisplay.blit(charL, (snakeList[-1][0], snakeList[-1][1]))
        proper = charL
    if direction == "right":
        gameDisplay.blit(charR, (snakeList[-1][0], snakeList[-1][1]))
        proper = charR
    if direction == "up":
        gameDisplay.blit(charU, (snakeList[-1][0], snakeList[-1][1]))
        proper = charU
    if direction == "down":
        gameDisplay.blit(charD, (snakeList[-1][0], snakeList[-1][1]))
        proper = charD



    for XnY in snakeList[:-1]:
        gameDisplay.blit(proper, [XnY[0],XnY[1],block_size,block_size])

def text_objects(text,color,size):
    if size == "small":
        textSurface = smallfont.render(text,True,color)
    elif size == "medium":
        textSurface = medfont.render(text,True,color)
    elif size == "tiny":
        textSurface = tinyfont.render(text,True,color)
    elif size == "smallmedium":
        textSurface = smallmedfont.render(text,True,color)
    elif size == "large":
        textSurface = largefont.render(text,True,color)

    return textSurface, textSurface.get_rect()

def text_to_button(msg,color,buttonx,buttony,buttonwidth,buttonheight,size = "small"):
    textSurf, textRect = text_objects(msg,color,size)
    textRect.center = ((buttonx + buttonwidth/2)), buttony+(buttonheight/2)
    gameDisplay.blit(textSurf, textRect)



def message_to_screen(msg,color, y_displace=0, size = "small"):
    textSurf, textRect = text_objects(msg,color,size)
    textRect.center = (display_width/2), (display_height/2)+ y_displace
    gameDisplay.blit(textSurf, textRect)


def button(text,x,y,width,height,inactive_color,active_color,size = "small",action = None):
    cur = pygame.mouse.get_pos()
    click = pygame.mouse.get_pressed()
    #print(click)
    if x + width > cur[0] > x and y + height > cur[1] > y:
        pygame.draw.rect(gameDisplay, active_color,(x,y,width,height))
        if click[0] == 1 and action != None:
            if action == "quit":
                pygame.quit()
                quit()
            elif action == "controls":
                game_intro = False
                game_controls()

            elif action == "play":
                game_intro = False
                gameLoop()
            elif action == "main":
                game_controls = False
                game_intro()
            elif action == "char":
                game_char()
            elif action == "mario":
                currentchar == "mario"

            elif currentchar == "mario":
                charU = pygame.image.load('mario up')
                charD = pygame.image.load('mario down')
                charL = pygame.image.load('mario left')
                charR = pygame.image.load('mario right')
                gameLoop()








    else:
        pygame.draw.rect(gameDisplay, inactive_color,(x,y,width,height))
    text_to_button(text,black,x,y,width,height,size)





def game_char():
    char = True
    while char:

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

        gameDisplay.fill(black)

        button("Mario",50,100,150,50,white,gray,"small",action = "goomba")
        button("Main Menu",320,500,150,50,white,gray,"tiny", action = "main")
        button("Quit",550,500,100,50,white,gray,"small", action = "quit")




        pygame.display.update()
        clock.tick(60)





def game_controls():
    gcont = True
    while gcont:

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

        gameDisplay.fill(black)
        gameDisplay.blit(cont,(0,0))

        button("Play",150,500,100,50,white,gray,"small",action = "play")
        button("Main Menu",320,500,150,50,white,gray,"tiny", action = "main")
        button("Quit",550,500,100,50,white,gray,"small", action = "quit")


        pygame.display.update()
        clock.tick(60)



def game_intro():
    intro = True
    while intro:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            elif event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_p:
                        intro = False
        gameDisplay.fill(black)
        gameDisplay.blit(imggg,(0,0))


        button("Play",150,500,100,50,white,gray,"small",action = "play")
        button("ControLs",320,500,150,50,white,gray,"tiny", action = "controls")
        button("Characters",295,425,200,50,white,gray,"tiny", action = "char")
        button(" ",0,0,0,0,white,gray,"tiny", action = "controls")
        button("Quit",550,500,100,50,white,gray,"small", action = "quit")








        pygame.display.update()
        clock.tick(60)








def gameLoop():
    global direction
    direction = "left"
    gameExit = False
    gameOver= False
    lead_y = display_height/2
    lead_x = display_width/2

    lead_x_change = -10
    lead_y_change = 0

    snakeList = []
    snakeLength = 1

    randAppleX, randAppleY = randAppleGen()

    while not gameExit:

        while gameOver == True:
##            gameDisplay.blit(loser,(0,0))
            message_to_screen("Game over",
                              red,y_displace=-50,size="large")

            message_to_screen("Press P to play again or Q to quit",
                              black,50,size="small")
            pygame.display.update()


            for event in pygame.event.get():
                if event.type == pygame.QUIT:

                    gameExit = True
                    gameOver = False

                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_q:
                        gameExit = True
                        gameOver = False
                    if event.key == pygame.K_p:
                        gameLoop()


        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                        gameExit = True
            if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_a:

                            direction = "left"
                            lead_x_change = -block_size
                            lead_y_change = 0
                    elif event.key == pygame.K_d:
                            direction = "right"
                            lead_x_change = block_size
                            lead_y_change = 0
                    elif event.key == pygame.K_w:
                            direction = "up"
                            lead_y_change = -block_size
                            lead_x_change = 0
                    elif event.key == pygame.K_s:
                            direction = "down"
                            lead_y_change = block_size
                            lead_x_change = 0
                    elif event.key == pygame.K_UP:
                            direction = "up"
                            lead_x_change = 0
                            lead_y_change = -block_size
                    elif event.key == pygame.K_DOWN:
                            direction = "down"
                            lead_y_change = block_size
                            lead_x_change = 0
                    elif event.key == pygame.K_LEFT:
                            direction = "left"
                            lead_x_change = -block_size
                            lead_y_change = 0
                    elif event.key == pygame.K_RIGHT:
                            direction = "right"
                            lead_x_change = block_size
                            lead_y_change = 0
                    elif event.key == pygame.K_ESCAPE:
                        pause()

        if lead_x >= display_width or lead_x < 0 or lead_y >= display_height or lead_y < 0:
            gameOver = True


        '''lead_x = (lead_x + lead_x_change) % 800 lead_y = (lead_y + lead_y_change) % 600'''

        lead_x += lead_x_change
        lead_y += lead_y_change



        gameDisplay.fill(gray)

        gameDisplay.blit(yum,(randAppleX,randAppleY))


        snakeHead = []
        snakeHead.append(lead_x)
        snakeHead.append(lead_y)
        snakeList.append(snakeHead)

        if len(snakeList)> snakeLength:
            del snakeList [0]

        snake(block_size, snakeList)

        for eachSegment in snakeList [:-1]:
            if eachSegment == snakeHead:
                gameOver = True

        snake(block_size, snakeList)

        score(snakeLength-1)

        pygame.display.update()



        if lead_x > randAppleX and lead_x < randAppleX + AppleThickness or lead_x + block_size > randAppleX and lead_x + block_size < randAppleX + AppleThickness:
            if lead_y > randAppleY and lead_y < randAppleY + AppleThickness or lead_y + block_size > randAppleY and lead_y + block_size < randAppleY + AppleThickness:
                randAppleX, randAppleY = randAppleGen()
                snakeLength += 1

            elif lead_y + block_size > randAppleY and lead_y + block_size < randAppleY + AppleThickness:
                randAppleX, randAppleY = randAppleGen()
                snakeLength += 1



        clock.tick(FPS)



    pygame.quit()
    quit()
game_intro()
gameLoop()