python飘落雪花圣诞树

以下是Python飘落雪花圣诞树的代码和效果演示：

import turtle
import random

# 设置画布大小和背景颜色
turtle.setup(800, 600)
turtle.bgcolor('black')

# 定义画笔
pen = turtle.Turtle()
pen.speed(0)
pen.color('white')
pen.penup()
pen.setpos(-200, -250)
pen.pendown()

# 定义圣诞树函数
def draw_tree(size, level):
    if level <= 0:
        return
    else:
        pen.pensize(size / 10)
        pen.forward(size)
        pen.right(20)
        draw_tree(size - random.randint(10, 20), level - 1)
        pen.left(40)
        draw_tree(size - random.randint(10, 20), level - 1)
        pen.right(20)
        pen.backward(size)

# 定义雪花函数
def draw_snowflake():
    pen.color('white')
    pen.penup()
    x = random.randint(-350, 350)
    y = random.randint(200, 250)
    pen.setpos(x, y)
    pen.pendown()
    for i in range(8):
        pen.forward(10)
        pen.backward(10)
        pen.left(45)

# 绘制圣诞树
draw_tree(100, 7)

# 飘落雪花
while True:
    draw_snowflake()
    pen.penup()
    pen.home()
    pen.pendown()

# 点击关闭窗口
turtle.done()

效果演示：