画一组同心圆
import turtle turtle.penup() turtle.goto(0,-200) turtle.pendown() turtle.circle(200) turtle.penup() turtle.goto(0,-150) turtle.pendown() turtle.circle(150) turtle.penup() turtle.goto(0,-100) turtle.pendown() turtle.circle(100) turtle.penup() turtle.goto(0,-50) turtle.pendown() turtle.circle(50)