使用turtle库绘制渐变的圆

import turtle as t
t.pensize(3)
t.pencolor("blue")
t.penup()
t.fd(-250)
t.seth(0)
t.pendown()
t.fillcolor("yellow")
t.begin_fill()
n=10
for i in range (3,n):
    t.circle(40,steps=i)
    t.penup()
    t.fd(80)
    t.seth(0)
    t.pendown()
t.penup()
t.fd(0)
t.seth(0)
t.pendown()
t.circle(40)
t.end_fill()