Dear all,

I am teaching myself python and pygame.

I took a simple example and modified it in order to understand how it works. My source code is here:

import pygame
import pygame.gfxdraw # not sure why needed
import random
pygame.init() # initialize the pygame module
screen = pygame.display.set_mode((800,450)) # set the window size
pygame.display.set_caption('Circles') # set the window title
pygame.mouse.set_visible(0) # hide the mouse pointer
screen.fill((0, 0, 0)) # fill the ascreen in black
while 1:
for event in pygame.event.get(): # read all the events
if event.type == pygame.QUIT: sys.exit() # was the x pressed
r=random.randint(0,255)
g=random.randint(0,255)
b=random.randint(0,255)
x=random.randint(0,800)
y=random.randint(0,450)
d=random.randint(0,800)
s = pygame.Surface(screen.get_size(), pygame.SRCALPHA, 32) # set the surface
pygame.gfxdraw.filled_circle(s, x, y, d, (r, g, b)) # draw a circle on the surface
screen.fill((0, 0, 0)) # clear the screen so all other objects removed
screen.blit(s, (0, 0)) # blit draws the screen
pygame.display.flip() # display the screen

My questions are:

1) If I import pygame, why do I need to seperately import pygame.gfxdraw?
2) Why do I need to set the surface and what does this do exactly?
3) Why do I need a screen.blit?

Hope someone can help so I can progress my learning!

1) pygame.gfxdraw is needed because not all module of pygame are imported by default
2) Surface is where you draw, ... imagine it that you draw in a buffer.
3) To transfer the buffer to the real screen. (to simplify as it s still a buffer)

I suggest you to read the documentation and particulary the examples :
http://www.pygame.org/docs/

And also this beginner tutorial : http://www.learningpython.com/2006/0...game-part-one/