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.speed (10)


turtle.setup(600,400,0,0)
turtle.color("yellow")
turtle.fillcolor("yellow")

turtle.up()
turtle.goto(-250,75)
turtle.down()

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

 

b.画同心圆

#同心圆
from turtle import*
speed (10)

for i in range(10):
    up()
    goto(0,-20*(i+1))
    down()
    circle(20*(i+1))

 

 

c.画太阳花

from turtle import*
speed (10)

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

 

d.画五个五角星

import turtle
turtle.speed(10)
turtle.bgcolor ("red")
turtle.color("yellow")
turtle.fillcolor("yellow")
turtle.begin_fill()

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

def it_star(a):
   for i in range(5):
         turtle.forward(a)
         turtle.right(144)
         
def it_left(b):
   turtle.left(b)
         
def it_right(b):
   turtle.right(b)
   

turtle.begin_fill() 
it_goto(-550,200)
it_star(200)
turtle.end_fill()

turtle.begin_fill()
it_goto(-260,300)
it_right(20)
it_star(50)
it_left(20)
turtle.end_fill()

turtle.begin_fill()
it_goto(-230,200)
it_left(20)
it_star(50)
it_right(20)
turtle.end_fill()

turtle.begin_fill()
it_goto(-230,130)
it_right(20)
it_star(50)
it_left(20)
turtle.end_fill()

turtle.begin_fill()
it_goto(-270,50)
it_right(20)
it_star(50)
it_left(20)
turtle.end_fill()

turtle.hideturtle()

 

e.画◇花瓣的太阳花。

import turtle
turtle.speed(10)
turtle.color('red')
turtle.fillcolor('yellow') 
turtle.begin_fill()
for i in range(36):      
    for j in range(2):        
        turtle.forward(100)
        turtle.right(45)
        turtle.forward(100)
        turtle.right(135)      
    turtle.right(10)
turtle.right(90)
turtle.forward(400)
turtle.end_fill()