绘制同心圆

 1 import turtle
 2 
 3 turtle.pensize(10)
 4 
 5 r=eval(input())
 6 n=eval(input())
 7 color=input()
 8 turtle.pencolor(color)
 9 
10 for i in range(n):
11     turtle.circle(r+(i-1)*20,360)#每个同心圆的半径差为20
12     turtle.penup()
13     turtle.right(90)
14     turtle.forward(20)
15     turtle.left(90)
16     turtle.pendown()