Keyboard drawing

import pygame, sys, random
from pygame.locals import *
def main():

    pygame.init()

    windowSurface = pygame.display.set_mode((750, 750), 0, 32)
    pygame.display.set_caption('colourBox')
    BLACK = (0, 0, 0)
    WHITE = (255, 255, 255)
    RED = (255, 0, 0)
    GREEN = (0, 255, 0)
    BLUE = (0, 0, 255)
    YELLOW = (255, 255, 0)
    COLOUR = WHITE
    FILL = BLACK
    paintStreak = False
    offsetX = 0
    offsetY = 0
    SPEED = {-1 : -8, 0 : 0, 1: 8}
    x = 325
    y = 325
    basicFont = pygame.font.SysFont(None, 48)
    textcolour = 0
    upperBound = 0
    lowerBound = 700
    leftBound =  0
    rightBound = 700
    windowSurface.fill(BLACK)
    pygame.draw.rect(windowSurface, WHITE, (x, y, 50, 50))
    pygame.display.update()



    def moveBox(x, y):
        while True:
            if paintStreak == False:
                pygame.draw.rect(windowSurface, FILL, (wipeX, wipeY, 50, 50))
            pygame.draw.rect(windowSurface, COLOUR, (x, y, 50, 50))
            pygame.display.update()
            return

    while True:
        if offsetX > 1:
            offsetX = 1
        if offsetX < -1:
            offsetX = -1
        if offsetY > 1:
            offsetY = 1
        if offsetY < -1:
            offsetY = -1
        wipeX = x
        wipeY = y
        x = x + SPEED[offsetX]
        y = y + SPEED[offsetY]
        if x > rightBound:
            x = rightBound
        if y > lowerBound:
            y = lowerBound
        if x < leftBound:
            x = leftBound
        if y < upperBound:
            y = upperBound

        moveBox(x, y)




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

                if event.key == K_UP:
                    offsetY -= 1
                if event.key == K_DOWN:
                    offsetY += 1
                if event.key == K_LEFT:
                    offsetX -= 1
                if event.key == K_RIGHT:
                    offsetX += 1
                if event.key == K_RETURN:
                    FILL = COLOUR
                    windowSurface.fill(FILL)
                if event.key == K_g:
                    COLOUR = GREEN
                if event.key == K_b:
                    COLOUR = BLUE
                if event.key == K_r:
                    COLOUR = RED
                if event.key == K_y:
                    COLOUR = YELLOW
                if event.key == K_n:
                    COLOUR = BLACK
                if event.key == K_w:
                    COLOUR = WHITE
                if event.key == K_EQUALS:
                    paintStreak = True
                if event.key == K_MINUS:
                    paintStreak = False



            if event.type == KEYUP:
                if event.key == K_UP:
                    offsetY += 1
                if event.key == K_DOWN:
                    offsetY -= 1
                if event.key == K_LEFT:
                    offsetX += 1
                if event.key == K_RIGHT:
                    offsetX -= 1

if __name__ == "__main__":
    main()