#coding=utf-8
import turtle
import mathdef draw_polygon(aTurtle, size=50, n=3):''' 绘制正多边形args:aTurtle: turtle对象实例size: int类型，正多边形的边长n: int类型，是几边形        '''for i in range(n):aTurtle.forward(size)aTurtle.left(360.0/n)def draw_n_angle(aTurtle, size=50, num=5, color=None):''' 绘制正n角形，默认为黄色args:aTurtle: turtle对象实例size: int类型，正多角形的边长n: int类型，是几角形    color: str， 图形颜色，默认不填色'''if color:aTurtle.begin_fill()aTurtle.fillcolor(color)for i in range(num):aTurtle.forward(size)aTurtle.left(360.0/num)aTurtle.forward(size)aTurtle.right(2*360.0/num)if color:aTurtle.end_fill()def draw_5_angle(aTurtle=None, start_pos=(0,0), end_pos=(0,10), radius=100, color=None):''' 根据起始位置、结束位置和外接圆半径画五角星args:aTurtle: turtle对象实例start_pos: int的二元tuple，要画的五角星的外接圆圆心end_pos: int的二元tuple，圆心指向的位置坐标点radius: 五角星外接圆半径color: str， 图形颜色，默认不填色    '''aTurtle = aTurtle or turtle.Turtle()size = radius * math.sin(math.pi/5)/math.sin(math.pi*2/5)aTurtle.left(math.degrees(math.atan2(end_pos[1]-start_pos[1], end_pos[0]-start_pos[0])))aTurtle.penup()aTurtle.goto(start_pos)aTurtle.fd(radius)aTurtle.pendown()aTurtle.right(math.degrees(math.pi*9/10))draw_n_angle(aTurtle, size, 5, color)def draw_5_star_flag(times=20.0):''' 绘制五星红旗args:times: 五星红旗的规格为30*20， times为倍数，默认大小为10倍， 即300*200'''width, height = 30*times, 20*times# 初始化屏幕和海龟window = turtle.Screen()aTurtle = turtle.Turtle()aTurtle.hideturtle()aTurtle.speed(10)# 画红旗aTurtle.penup()aTurtle.goto(-width/2, height/2)aTurtle.pendown()aTurtle.begin_fill()aTurtle.fillcolor('red')aTurtle.fd(width)aTurtle.right(90)aTurtle.fd(height)aTurtle.right(90)aTurtle.fd(width)aTurtle.right(90)aTurtle.fd(height)aTurtle.right(90)    aTurtle.end_fill()# 画大星星draw_5_angle(aTurtle, start_pos=(-10*times, 5*times), end_pos=(-10*times, 8*times), radius=3*times, color='yellow')  # 画四个小星星stars_start_pos = [(-5, 8), (-3, 6), (-3, 3), (-5, 1)]for pos in stars_start_pos:draw_5_angle(aTurtle, start_pos=(pos[0]*times, pos[1]*times), end_pos=(-10*times, 5*times), radius=1*times, color='yellow')  # 点击关闭窗口window.exitonclick()if __name__ == '__main__':draw_5_star_flag()