from turtle import *

from random import *

from math import *

import turtle

import time

def tree(n, l):

pd() # 下笔

# 阴影效果

t = cos(radians(heading() + 45)) / 8 + 0.25

pencolor(t, t, t)

pensize(n / 3)

forward(l) # 画树枝

if n > 0:

b = random() * 15 + 10 # 右分支偏转角度

c = random() * 15 + 10 # 左分支偏转角度

d = l * (random() * 0.25 + 0.7) # 下一个分支的长度

# 右转一定角度，画右分支

right(b)

tree(n - 1, d)

# 左转一定角度，画左分支

left(b + c)

tree(n - 1, d)

# 转回来

right(c)

else:

# 画叶子

right(90)

n = cos(radians(heading() - 45)) / 4 + 0.5

pencolor(n, n*0.8, n*0.8)

circle(3)

left(90)

# 添加0.3倍的飘落叶子

if(random() > 0.7):

pu()

# 飘落

t = heading()

an = -40 + random()*40

setheading(an)

dis = int(800*random()*0.5 + 400*random()*0.3 + 200*random()*0.2)

forward(dis)

setheading(t)

# 画叶子

pd()

right(90)

n = cos(radians(heading() - 45)) / 4 + 0.5

pencolor(n*0.5+0.5, 0.4+n*0.4, 0.4+n*0.4)

circle(2)

left(90)

pu()

#返回

t = heading()

setheading(an)

backward(dis)

setheading(t)

pu()

backward(l)# 退回

bgcolor(0.5, 0.5, 0.5) # 背景色

ht() # 隐藏turtle

speed(0) # 速度，1-10渐进，0最快

tracer(0, 0)

pu() # 抬笔

backward(100)

left(90) # 左转90度

pu() # 抬笔

backward(300) # 后退300

tree(12, 100) # 递归7层

def move_pen_position(x, y):

turtle.hideturtle() # 隐藏画笔(先)

turtle.up() # 提笔

turtle.goto(x, y) # 移动画笔到指定起始坐标(窗口中心为0,0)

turtle.down() # 下笔

turtle.showturtle() # 显示画笔

signature = '我爱你\n就像风走了八百里不问归期'

name = '❤'

turtle.screensize(800, 600)

turtle.color('red', 'pink')

time.sleep(2)

move_pen_position(220, -180)

turtle.hideturtle() # 隐藏画笔

turtle.write(signature, font=('Arial', 20), align="center")

move_pen_position(220, -220)

turtle.hideturtle() # 隐藏画笔

turtle.color('black', 'pink')

turtle.write(name, font=('Arial', 20), align="center")

turtle.done()

done()