条件、循环、函数定义 练习

注意标准库的两种导入与使用方式，建议大家采用<库名>.<函数名>的方式。

对前面的代码进行优化，用for,while,if,def实现：

1. 画五角星

   import turtle
   for i in range(5):
       turtle.forward(100)
       turtle.right(144)

    

2. 画同心圆

   import turtle
   for i in range(5):
       turtle.up()
       turtle.goto(0,-20*(1+i))
       turtle.down()
       turtle.circle(20*(1+i))

    

3. 画太阳花

   import turtle
   while True:
       turtle.forward(200)
       turtle.left(170)
   if(abs(turtle.pos()))<1:
   break

    

4. 画五个角星

   import turtle
   turtle.speed(10)
   turtle.bgcolor('red')
   
   def goto(x,y):
       turtle.up()
       turtle.goto(x,y)
       turtle.down()
   
   def draw(r):
       turtle.color('yellow')
       turtle.fillcolor('yellow')
       turtle.begin_fill()
   for i in range(5):
           turtle.forward(r)
           turtle.right(144)
       turtle.end_fill()
   
   goto(-550,200)
   draw(230)
   
   goto(-260,280)
   turtle.left(45)
   draw(60)
   
   goto(-165,175)
   turtle.left(50)
   draw(60)
   
   goto(-185,100)
   turtle.right(95)
   draw(60)
   
   goto(-260,0)
   turtle.left(45)
   draw(60)
   
   turtle.hideturtle()

    

    

5. 画◇花瓣的太阳花

   import turtle
   def my_lx(brad):
       brad.forward(100)
       brad.right(45)
       brad.forward(100)
       brad.right(135)
   
   def my_art():
       window=turtle.Screen()
       window.bgcolor("purple")
       brad=turtle.Turtle()
       brad.shape("turtle")
       brad.color("orange")
       brad.speed('fastest')
   for i in range(1,37):
           my_lx(brad)
           my_lx(brad)
           brad.left(10)
       brad.right(90)
       brad.forward(300)
   my_art()