how to choose wher a pygame window appears code example
Example 1: how to set the location on a pygame window
pos_x = screen_width / 2 - window_width / 2
pos_y = screen_height - window_height
os.environ['SDL_VIDEO_WINDOW_POS'] = '%i,%i' % (pos_x,pos_y)
os.environ['SDL_VIDEO_CENTERED'] = '0'
Example 2: pygame window at center
import pygame, os
os.environ['SDL_VIDEO_CENTERED'] = '1'
# This has to be done before you initialise pygame with pygame.init()