Python：Turtle图形绘制

Turtle库

Turtle 库是 Python 中一个绘制图像的函数库，想象一个小乌龟，在x，y坐标系原点有一只小乌龟，它根据函数指令的控制在坐标系中移动，从而在爬行的路径上绘制出图形。

demo1.正方形螺旋线的绘制

（1）利用 turtle 库绘制一个正方形螺旋线

import turtle
turtle.speed("fastest")
turtle.pensize(2)
for x in range(100):
    turtle.forward(2*x)
    turtle.left(90)
turtle.done()

（2）绘制斜螺旋线

import turtle
turtle.speed("fastest")
turtle.pensize(2)
for x in range(100):
    turtle.forward(2*x)
    turtle.left(91)
turtle.done()

（3）绘制彩色斜螺旋线

import turtle
turtle.speed("fastest")
turtle.pensize(2)
colors=['red','yellow','purple','blue']
for x in range(100):
    turtle.pencolor(colors[x%4])
    turtle.forward(2*x)
    turtle.left(91)
turtle.done()

demo2.经典蟒蛇的绘制

（1）turtle库绘制蟒蛇

import turtle
turtle.penup()
turtle.fd(-250)
turtle.pendown()
turtle.pensize(25)
turtle.pencolor('purple')
turtle.seth(-40)#改变海龟的行进方向，参数为绝对角度
for i in range(4):
    turtle.circle(40,80)
    turtle.circle(-40,80)
turtle.circle(40,80/2)
turtle.fd(40)
turtle.circle(16,180)
turtle.fd(40*2/3)
turtle.done()

（2）绘制彩色蟒蛇

import turtle
turtle.setup(650,350,200,200)
colors=['purple','red','yellow','pink','blue','green']
turtle.penup()
turtle.fd(-250)
turtle.pendown()
turtle.pensize(25)
turtle.seth(-40)
for i in range(5):
    turtle.pencolor(colors[i])
    turtle.circle(40,80)
    turtle.circle(-40,80)
turtle.pencolor(colors[5])
turtle.circle(40,80/2)
turtle.fd(40)
turtle.circle(16,180)
turtle.fd(40*2/3)
turtle.done()

demo3.绘制奥运五环图

import turtle
colors=['blue','black','red','yellow','green']
turtle.pensize(10)

for i in range(5):
    turtle.pencolor(colors[i])
    if i<3:
        #绘制上三个环
        turtle.goto(120*i,0)
        turtle.pendown()
        turtle.circle(50)
        turtle.penup()
    else:
        #下两个环
        turtle.goto(60+120*(i-3),-50)
        turtle.pendown()
        turtle.circle(50)
        turtle.penup()
turtle.done()