from turtle import *
from random import *
# 绘制随机雪花
def DrawSnow(snow):
 x = randrange(-750, 750)
 y = randrange(-50, 400)
 snowcolor = (randrange(0, 255), randrange(0, 255), randrange(0, 255))
 snowsize = randrange(10, 20)
 snowstyle = choice([30, 45])
 snow.penup()
 snow.setpos(x, y)
 snow.pendown()
 colormode(255)
 snow.pencolor(snowcolor)
 for i in range(int(360/snowstyle)):
 if snowsize < 11:
  snowstyle = 90
 snow.forward(snowsize)
 snow.backward(snowsize)
 snow.right(snowstyle)
#绘制上半部分雪花
def InitSnow(n):
 snow = Turtle()
 for i in range(n):
 DrawSnow(snow)
#绘制下半部分雪地
def InitField():
 field = Turtle()
 colormode(255)
 for i in range(300):
 x = randrange(-850, 850)
 y = randrange(-400, 0)
 width = randrange(50, 200)
 length = randrange(3, 8)
 field.penup()
 field.setpos(x, y)
 field.pendown()
 tempcolor = int(-255 * y/400)
 print(tempcolor)
 fieldcolor = (tempcolor, tempcolor, tempcolor)
 field.color(fieldcolor, fieldcolor)
 field.begin_fill()
 field.fd(width)
 field.circle(length, 180)
 field.fd(width)
 field.circle(length, 180)
 field.end_fill()
 
def main():
 bgcolor("black")
 tracer(False)
 InitField()
 InitSnow(200)
 tracer(True)
 mainloop()
 
if __name__ == '__main__':
 main()