条件、循环、函数定义 练习

1.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。

2.对前面的代码进行优化，用for,while,if,def实现：

a.画五角星

import turtle
turtle.shape('turtle')
turtle.color('yellow')
turtle.fillcolor('yellow')

turtle.begin_fill()
for i in range(5):
    turtle.forward(100)
    turtle.right(144)
turtle.end_fill()
turtle.hideturtle()
turtle.done()

b.画同心圆

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

c.画太阳花

import turtle
turtle.color('red','yellow')
turtle.begin_fill()
while True:
    turtle.forward(200)
    turtle.left(170)
    if(abs(turtle.pos()))<1:
        break
turtle.end_fill()
turtle.hideturtle()
turtle.done()

 

d.画五个五角星

 

import turtle

turtle.bgcolor('red')
turtle.color('yellow')
turtle.fillcolor('yellow')

def my_goto(x,y):
    turtle.up()
    turtle.goto(x,y)
    turtle.down()

def my_draw(r):
    turtle.begin_fill()
    for i in range(5):
        turtle.forward(r)
        turtle.right(144)
    turtle.end_fill()

my_goto(-350,180)
my_draw(150)

my_goto(-175,250)
turtle.left(50)
my_draw(50)

my_goto(-100,175)
turtle.left(44)
my_draw(50)

my_goto(-70,80)
turtle.left(44)
my_draw(50)

my_goto(-140,50)
turtle.left(50)
my_draw(50)

turtle.hideturtle()
turtle.done()

e.画◇花瓣的太阳花。

 

import turtle

def my_draw1(brad):
    brad.forward(100)
    brad.right(45)
    brad.forward(100)
    brad.right(135)

def my_draw2():
    window=turtle.Screen()
    window.bgcolor('blue')

    brad=turtle.Turtle()
    brad.shape('turtle')
    brad.color('yellow')
    brad.speed('fastest')

    for i in range(1,37):
        my_draw1(brad)
        my_draw1(brad)
        brad.left(10)

    brad.right(90)
    brad.forward(300)

    window.exitonclick()

my_draw2()