#繪製彩色螺旋線
import turtle
import time
turtle.pensize(2)
turtle.bgcolor("black")
colors = ["red","yellow","purple","blue"]
turtle.tracer(False)
for x in range(400):
    turtle.forward(2*x)
    turtle.color(colors[x % 4])
    turtle.left(91)
turtle.tracer(True)
# input() 可以有效解決閃退問題，或者下面的方法
time.sleep(20)