python学习--交互式图形编程实例四

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#画雪

from turtle import *
from random import *   
 
def ground():
    hideturtle()
    speed(100)
    for i in range(400):
        pensize(randint(5,10)) #画笔大小随机
        x = randint(-400,350)
        y = randint(-280,-1)
        r = -y/280 #<1的随机值
        g = -y/280 #<1的随机值
        b = -y/280 #<1的随机值
        pencolor((r, g, b))
        penup()
        goto(x,y)
        pendown()
        forward(randint(40,100)) #随机画40 - 100 的线条
 
def snow():    
    hideturtle()
    pensize(2)
    speed(100)
    for i in range(100):
        r = random() #随机值
        g = random() #随机值
        b = random() #随机值
        pencolor(r, g, b)
        penup()
        setx(randint(-350,350)) 
        sety(randint(1,270))
        pendown()
        dens = randint(8,12)
        snowsize = randint(10,14)
        for j in range(dens):
            forward(snowsize) #前进
            backward(snowsize) #后退
            right(360/dens) #旋转角度
         
 
def main():
    setup(800, 600, 0, 0) #设置画布大小
    tracer(False) #不显示动画
    bgcolor("black")    
    snow()
    ground()
    tracer(True)
    mainloop()
     
if __name__ == "__main__":
    main()

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#画彩虹

from turtle import *
 
def HSB2RGB(hues):
    hues = hues * 3.59 #100转成359范围
    rgb=[0.0,0.0,0.0]
    i = int(hues/60)%6
    f = hues/60 -i
    if i == 0:
        rgb[0] = 1; rgb[1] = f; rgb[2] = 0
    elif i == 1:
        rgb[0] = 1-f; rgb[1] = 1; rgb[2] = 0
    elif i == 2:
        rgb[0] = 0; rgb[1] = 1; rgb[2] = f
    elif i == 3:
        rgb[0] = 0; rgb[1] = 1-f; rgb[2] = 1
    elif i == 4:
        rgb[0] = f; rgb[1] = 0; rgb[2] = 1
    elif i == 5:
        rgb[0] = 1; rgb[1] = 0; rgb[2] = 1-f
    return rgb
     
def rainbow():
    hues = 0.0
    color(1,0,0)
    #绘制彩虹
    hideturtle()
    speed(100)
    pensize(3)
    penup()
    goto(-400,-300)
    pendown()
    right(110)
    for i in range (100):
        circle(1000)
        right(0.13)
        hues = hues + 1
        rgb = HSB2RGB(hues)
        color(rgb[0],rgb[1],rgb[2])    
    penup()
     
def main():
    setup(800, 600, 0, 0)
    bgcolor((0.8, 0.8, 1.0))
    tracer(False)
    rainbow()
    #输出文字
    tracer(False)
    goto(100,-100)
    pendown()
    color("red")
    write("Rainbow",align="center",
          font=("Script MT Bold", 80, "bold"))
    tracer(True)
     
    mainloop()
 
if __name__ == "__main__":
    main()