Python Turtle库画树

一、树形1

代码：

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()

二、树形2

效果图：

代码：

from turtle import *

# 设置色彩模式是RGB:
colormode(255)

lt(90)

lv = 14
l = 120
s = 45

width(lv)

# 初始化RGB颜色:
r = 0
g = 0
b = 0
pencolor(r, g, b)

penup()
bk(l)
pendown()
fd(l)

def draw_tree(l, level):
    global r, g, b
    # save the current pen width
    w = width()

    # narrow the pen width
    width(w * 3.0 / 4.0)
    # set color:
    r = r + 1
    g = g + 2
    b = b + 3
    pencolor(r % 200, g % 200, b % 200)

    l = 3.0 / 4.0 * l

    lt(s)
    fd(l)

    if level < lv:
        draw_tree(l, level + 1)
    bk(l)
    rt(2 * s)
    fd(l)

    if level < lv:
        draw_tree(l, level + 1)
    bk(l)
    lt(s)

    # restore the previous pen width
    width(w)

speed("fastest")

draw_tree(l, 4)

done()

三、树形3

效果图：

代码：

import turtle
import random
from turtle import *
from time import sleep

t = turtle.Turtle()
w = turtle.Screen()

def tree(branchLen, t):
    if branchLen > 3:
        if 8 <= branchLen <= 12:
            if random.randint(0, 2) == 0:
                t.color('snow')
            else:
                t.color('lightcoral')
            t.pensize(branchLen / 3)
        elif branchLen < 8:
            if random.randint(0, 1) == 0:
                t.color('snow')
            else:
                t.color('lightcoral')
            t.pensize(branchLen / 2)
        else:
            t.color('sienna')
            t.pensize(branchLen / 10)

        t.forward(branchLen)
        a = 1.5 * random.random()
        t.right(20*a)
        b = 1.5 * random.random()
        tree(branchLen-10*b, t)
        t.left(40*a)
        tree(branchLen-10*b, t)
        t.right(20*a)
        t.up()
        t.backward(branchLen)
        t.down()


def petal(m, t):  # 树下花瓣
    for i in range(m):
        a = 200 - 400 * random.random()
        b = 10 - 20 * random.random()
        t.up()
        t.forward(b)
        t.left(90)
        t.forward(a)
        t.down()
        t.color("lightcoral")
        t.circle(1)
        t.up()
        t.backward(a)
        t.right(90)
        t.backward(b)


def main():
    t = turtle.Turtle()
    myWin = turtle.Screen()
    getscreen().tracer(5, 0)
    turtle.screensize(bg='wheat')
    t.left(90)
    t.up()
    t.backward(150)
    t.down()
    t.color('sienna')
    tree(60, t)
    petal(100, t)

    myWin.exitonclick()

main()
done()

 

四、树形4

效果图

代码：

from turtle import *
from random import *
from math import *

def tree(n, l):
    pd()
    t = cos(radians(heading() + 45)) / 8 + 0.25
    pencolor(t, t, t)
    pensize(n / 4)
    forward(l)
    if n > 0:
        b = random() * 15 + 10
        c = random() * 15 + 10
        d = l * (random() * 0.35 + 0.6)
        right(b)
        tree(n - 1, d)
        left(b + c)
        tree(n - 1, d)
        right(c)
    else:
        right(90)
        n = cos(radians(heading() - 45)) / 4 + 0.5
        pencolor(n, n, n)
        circle(2)
        left(90)
    pu()
    backward(l)

bgcolor(0.5, 0.5, 0.5)
ht()
speed(0)
tracer(0, 0)
left(90)
pu()
backward(300)
tree(13, 100)
done()