Python random colors flickering on object -

the following function defines rectangles, x/y location, width , height, , color. color randomly chosen every time.

def things(thingx, thingy, thingw, thingh, color):     rand_color = (random.randrange(0,255),random.randrange(0,255),random.randrange(0,255))     pygame.draw.rect(gamedisplay, rand_color, [thingx, thingy, thingw, thingh]) 

the current code causing program flicker through every different color. if change rand_color variation of choosing between black , white, rectangle flickers between black , white. what's happening here?

as said in comment, function generates different color each time it's called , flickering problem result of calling often. fix making rand_color global , define value outside function before it's ever called.

however think idea in john rodger's answer of using class one, implement differently , try take advantage of object-oriented programming instead of reinventing whole wheel. below runnable example of mean. every time run it, generate randomly colored rectangle represent thing object, , color not change or flicker display's updated.

import pygame, sys pygame.locals import * import random  fps = 30  # frames per second black = (0, 0, 0) white = (255, 255, 255)  class thing(pygame.rect):     def __init__(self, *args, **kwargs):         super(thing, self).__init__(*args, **kwargs)  # init rect base class         # define additional attributes         self.color = tuple(random.randrange(0, 256) _ in range(3))         self.x_speed, self.y_speed = 5, 5  # how fast moves      def draw(self, surface, width=0):         pygame.draw.rect(surface, self.color, self, width)  def main():     pygame.init()     fpsclock = pygame.time.clock()     pygame.key.set_repeat(250)  # enable keyboard repeat held down keys     gamedisplay = pygame.display.set_mode((500,400), 0,32)     gamedisplay.fill(white)      thingx,thingy, thingw,thingh = 200,150, 100,50     thing = thing(thingx, thingy, thingw, thingh)  # create instance      while true:  # display update loop         gamedisplay.fill(white)          event in pygame.event.get():             if event.type == quit:                 pygame.quit()                 sys.exit()             elif event.type == keydown:                 if event.key == k_down:                     thing.y += thing.y_speed                 elif event.key == k_up:                     thing.y -= thing.y_speed                 elif event.key == k_right:                     thing.x += thing.x_speed                 elif event.key == k_left:                     thing.x -= thing.x_speed          thing.draw(gamedisplay)  # display @ current position         pygame.display.update()         fpsclock.tick(fps)  main()