2.画一组同心圆

 1 ‘‘‘方法一
 2 from turtle import *
 3 setup(600,400,500,200)
 4 color("red")
 5 pensize(2)
 6 circle(20)
 7 for i in range(1,4):
 8     penup()
 9     goto(0,-10*i)
10     pendown()
11     circle(20+i*10)
12 hideturtle()
13 done()‘‘‘
14 
15 #方法二
16 import turtle
17 turtle.setup(600,400,500,200)
18 turtle.color("red")
19 turtle.pensize(2)
20 turtle.circle(20)
21 for i in range(1,4):
22     turtle.penup()
23     turtle.goto(0,-10*i)
24     turtle.pendown()
25     turtle.circle(20+i*10)
26 turtle.hideturtle()
27 turtle.done()