Python实战示例 画樱花树.zip

from turtle import * from random import * from math import * 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 done()