A simple turtle application.

sine.py

import math
import turtle

x = -700
a = 0.0

wn = turtle.Screen()
wn.bgcolor('lightblue')

fred = turtle.Turtle()
wn.clear()

fred.penup();

while True:
    fred.pendown()
    x = x + 5
    if x > 700:
        wn.clear()
        x = -700
    for angle in range(-20, 20):
        y = math.sin(math.radians(angle))
        a = y
        fred.goto(x, y*100)
        print(y*1000)
        x = x + 5
        if x > turtle.window_width()/2:
            wn.clear()
            x = -700