sine.py

import math
import pygame
from pygame import draw
import sys
import time

pygame.init() 
size = width, height = 500, 200
screen = pygame.display.set_mode(size)

scale = 35

offset = 0

while True:
    
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
    
    screen.fill(0xffffff)
    
    for i in xrange(0, width / scale + 1):
        x = (i * scale) - ((offset * scale) % scale)
        draw.line(screen, 0xa0a0a0, (x, 0), (x, height))
    
    for i in xrange(0, height / scale / 2 + 1):
        y = i * scale
        draw.line(screen, 0xa0a0a0, (0, height/2 + y), (width, height/2 + y))
        draw.line(screen, 0xa0a0a0, (0, height/2 - y), (width, height/2 - y))
    
    for x in xrange(0, width):
        y = math.sin(float(x) / scale + offset) * scale + (height * 0.5)
        draw.circle(screen, 0x00ff00, (x, int(y)), 1)
        
    pygame.display.flip()
    offset += 0.05
    time.sleep(.008)