小海龟历险记
Shawn
python3.7
文档：
https://docs.python.org/3/library/turtle.html
- 想象一下,把一个小海龟扔到沙滩上.小海龟爬啊爬,沙滩上留下来一道道痕迹,这就是turtle模块.
小海龟的动作
爬行
前进:forward/fd
turtle.forward(distance)
turtle.fd(distance)
Parameters: distance – a number (integer or float)
后退:back/bk/backward
turtle.back(distance)
turtle.bk(distance)
turtle.backward(distance)
Parameters: distance – a number (integer or float)
右拐(顺时针转):right/rt
turtle.right(angle)
turtle.rt(angle)
Parameters: distance – a number (integer or float)
左拐(逆时针转):left/lt
turtle.left(angle)
turtle.lt(angle)
Parameters: angle – a number (integer or float)
爬到指定位置:goto/setpos/setposition
turtle.goto(x, y=None)
turtle.setpos(x, y=None)
turtle.setposition(x, y=None)
Parameters:
x – a number or a pair/vector of numbers
y – a number or None
x轴上移动:setx
turtle.setx(x)
Parameters: x – a number (integer or float)
y轴上移动:sety
turtle.sety(y)
Parameters: y – a number (integer or float)
转向指定方向:setheading/seth
turtle.setheading(to_angle)
turtle.seth(to_angle)
Parameters: to_angle – a number (integer or float)
- 小海龟朝向指定方向.
- 注意,默认的方向可能有所不同:
| standard mode |
logo mode |
| 0 - east |
0 - north |
| 90 - north |
90 - east |
| 180 - west |
180 - south |
| 270 - south |
270 - west |
回家:home
turtle.home()
- 小海龟回到图像原点(0,0),并朝向默认初始方向.
画圆:circle
turtle.circle(radius, extent=None, steps=None)
Parameters:
radius – a number
extent – a number (or None)
steps – an integer (or None)
- 小海龟从当前位置开始向前画半径为radius,角度为extent的圆弧.
- radius为正,则逆时针,反之顺时针.
- 在turtle里,本质上,画圆弧相当于画n段直线.
- 用steps可以指定n的数量.换而言之,可以用于实现一些多边形.
画点:dot
turtle.dot(size=None, *color)
Parameters:
size – an integer >= 1 (if given)
color – a colorstring or a numeric color tuple
- 在当前位置画一个直径为size,颜色为color的点.
- 如果没有指定size,会默认选择max(当前笔粗+4,当前笔粗*2)
海龟分身:stamp
turtle.stamp()
- 在当前位置保存一个一模一样小海龟幻象,并返回这个幻象的id.
分身解除:clearstamp
turtle.clearstamp(stampid)
Parameters: stampid – an integer, must be return value of previous stamp() call
批量分身解除:clearstamps
turtle.clearstamps(n=None)
Parameters: n – an integer (or None)
- 批量解除分身.
- 默认全部,若n为正则解除最早n个,为负责解除最晚n个.
时光回溯:undo
turtle.undo()
调速:speed
turtle.speed(speed=None)
Parameters: speed – an integer in the range 0..10 or a speedstring (see below)
- “fastest”: 0
- “fast”: 10
- “normal”: 6
- “slow”: 3
“slowest”: 1
调节小海龟爬行以及转向的速度.
- 从1到10逐步加快,也可以设定为最快:0.
- 注意:小于等于0.5或者大于10都会被直接设定为0
海龟状态查询
海龟位置:position/pos
turtle.position()
turtle.pos()
小海龟的头部与目标间的角度:towards
turtle.towards(x, y=None)
Parameters:
x – a number or a pair/vector of numbers or a turtle instance
y – a number if x is a number, else None
- 返回小海龟当前方向与指定坐标(或者另一个海龟实体)连线的夹角.
x坐标查询:xcor
turtle.xcor()
y坐标查询:ycor
turtle.ycor()
当前方向:heading
turtle.heading()
距离查询:distance
turtle.distance(x, y=None)
Parameters:
x – a number or a pair/vector of numbers or a turtle instance
y – a number if x is a number, else None
- 返回小海龟与指定坐标(或者另一个海龟实体)间的距离.
定制规则
一圈有多少度:degrees
turtle.degrees(fullcircle=360.0)
Parameters: fullcircle – a number
- 设定一圈有多少度.如果你填400,那在小海龟的世界里一圈会被划分成400份而不是360份.
用弧度:radians
turtle.radians()
画笔
下笔(肚皮贴地):pendown/pd/down
turtle.pendown()
turtle.pd()
turtle.down()
抬笔(肚皮离地):penup/pu/up
turtle.penup()
turtle.pu()
turtle.up()
笔粗:pensize/width
turtle.pensize(width=None)
turtle.width(width=None)
Parameters: width – a positive number
画笔(海龟)状态总控:pen
turtle.pen(pen=None, **pendict)
Parameters:
pen – a dictionary with some or all of the below listed keys
pendict – one or more keyword-arguments with the below listed keys as keywords
- 可以调节\查询当前画笔的状态.
- “shown”: True/False
- “pendown”: True/False
- “pencolor”: color-string or color-tuple
- “fillcolor”: color-string or color-tuple
- “pensize”: positive number
- “speed”: number in range 0..10
- “resizemode”: “auto” or “user” or “noresize”
- “stretchfactor”: (positive number, positive number)
- “outline”: positive number
- “tilt”: number
是否在画:isdown
turtle.isdown()
颜色控制
画笔颜色:pencolor
turtle.pencolor(*args)
- 设定画笔颜色:
- 无参数:返回当前画笔颜色.
- 颜色名字符串或TKcolor字符串:设定颜色
- ”red”, “yellow”, “#33cc8c”
- rgb元组或rgb单值:设定颜色
- (0.2, 0.8, 0.55),(51.0, 204.0, 140.0)
- 255模式或者1.0模式由colormode()设定:
- colormode(255)
- colormode(1)
填充颜色: fillcolor
turtle.fillcolor(*args)
颜色总控:color
turtle.color(*args)
- 同时查询\设定画笔颜色与填充颜色.
- 第一组参数为画笔颜色.
- 第二组参数为填充颜色.
填充控制
填充状态:filling
turtle.filling()
开始填充:begin_fill
turtle.begin_fill()
正式填充:end_fill
turtle.end_fill()
- 计算从上一个begin_fill开始的图形,并进行填充.
更多骚操作
初始化:reset
turtle.reset()
清理沙滩:clear
turtle.clear()
写字:write
turtle.write(arg, move=False, align="left", font=("Arial", 8, "normal"))
Parameters:
arg – object to be written to the TurtleScreen
move – True/False
align – one of the strings “left”, “center” or right”
font – a triple (fontname, fontsize, fonttype)
其他海龟参数
海龟可见
隐藏海龟:hideturtle/ht
turtle.hideturtle()
turtle.ht()
显示海龟:showturtle/st
turtle.showturtle()
turtle.st()
海龟可见状态查询:isvisible
turtle.isvisible()
海龟外观
海龟外形:shape
turtle.shape(name=None)
Parameters: name – a string which is a valid shapename
- “arrow”, “turtle”, “circle”, “square”, “triangle”, “classic”
- 小海龟可以变身成圆圈\三角等
海龟大小缩放:resizemode
turtle.resizemode(rmode=None)
Parameters: rmode – one of the strings “auto”, “user”, “noresize”
- 设定海龟大小缩放模式:
- “auto”: adapts the appearance of the turtle corresponding to the value of pensize.
- “user”: adapts the appearance of the turtle according to the values of stretchfactor and outlinewidth (outline), which are set by shapesize().
- “noresize”: no adaption of the turtle’s appearance takes place.
海龟大小详细设置:shapesize/turtlesize
turtle.shapesize(stretch_wid=None, stretch_len=None, outline=None)
turtle.turtlesize(stretch_wid=None, stretch_len=None, outline=None)
Parameters:
stretch_wid – positive number
stretch_len – positive number
outline – positive number
海龟剪切系数:shearfactor
turtle.shearfactor(shear=None)
Parameters: shear – number (optional)
海龟外形旋转:tilt/settiltangle
turtle.tilt(angle)
turtle.settiltangle(angle)
Parameters: angle – a number
- 旋转海龟外形.
- 不同的是tilt会根据当前angle做出调整.
- 而settiltangle为绝对角度.
海龟外形角度查询:tiltangle
turtle.tiltangle(angle=None)
Parameters: angle – a number (optional)
- 返回当前外观角度.
- 如果有参数,效果同settiltangle.
turtle.shapetransform(t11=None, t12=None, t21=None, t22=None)
Parameters:
t11 – a number (optional)
t12 – a number (optional)
t21 – a number (optional)
t12 – a number (optional)
- 返回(设置)当前海龟外形变形参数(参照shapesize\shearfactor\settiltangle).
海龟外观获取:get_shapepoly
turtle.get_shapepoly()
事件监听器
监听器:listen
turtle.listen(xdummy=None, ydummy=None)
Set focus on TurtleScreen (in order to collect key-events). Dummy arguments are provided in order to be able to pass listen() to the onclick method.
监听鼠标按键按下:onclick
turtle.onclick(fun, btn=1, add=None)
Parameters:
fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
num – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding
监听鼠标按键抬起:onrelease
turtle.onrelease(fun, btn=1, add=None)
Parameters:
fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
num – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding
监听鼠标按键拖动:ondrag
turtle.ondrag(fun, btn=1, add=None)
Parameters:
fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
num – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding
监听键盘按键:onkey/onkeyrelease/onkeypress
turtle.onkey(fun, key)
turtle.onkeyrelease(fun, key)
turtle.onkeypress(fun, key=None)
Parameters:
fun – a function with no arguments or None
key – a string: key (e.g. “a”) or key-symbol (e.g. “space”)
定时操作:ontimer
turtle.ontimer(fun, t=0)
Parameters:
fun – a function with no arguments
t – a number >= 0
时间循环:mainloop/done
turtle.mainloop()
turtle.done()
Starts event loop - calling Tkinter’s mainloop function. Must be the last statement in a turtle graphics program. Must not be used if a script is run from within IDLE in -n mode (No subprocess) - for interactive use of turtle graphics.
更多海龟操作
开始记录多边形:begin_poly
turtle.begin_poly()
结束记录多边形:end_poly
turtle.end_poly()
获取记录到的多边形:get_poly
turtle.get_poly()
克隆海龟:clone
turtle.clone()
查询海龟:getturtle/getpen
turtle.getturtle()
turtle.getpen()
查询屏幕:getscreen
turtle.getscreen()
设定undobuffer:setundobuffer
turtle.setundobuffer(size)
Parameters: size – an integer or None
- 设定一个undobuffer,记录最多size步可以由undo反悔的海龟操作.
- 如果size为None,则关闭这个buffer.
查询undobuffer:undobufferentries
turtle.undobufferentries()
Screen/TurtleScreen操作
窗口控制
背景色:bgcolor
turtle.bgcolor(*args)
Parameters: args – a color string or three numbers in the range 0..colormode or a 3-tuple of such numbers
背景图:bgpic
turtle.bgpic(picname=None)
Parameters: picname – a string, name of a gif-file or "nopic", or None
- 设定或返回背景图,picname可以是文件名,如果为’nopic’则删除背景图.
窗口size:screensize
turtle.screensize(canvwidth=None, canvheight=None, bg=None)
Parameters:
canvwidth – positive integer, new width of canvas in pixels
canvheight – positive integer, new height of canvas in pixels
bg – colorstring or color-tuple, new background color
world坐标:setworldcoordinates
turtle.setworldcoordinates(llx, lly, urx, ury)
Parameters:
llx – a number, x-coordinate of lower left corner of canvas
lly – a number, y-coordinate of lower left corner of canvas
urx – a number, x-coordinate of upper right corner of canvas
ury – a number, y-coordinate of upper right corner of canvas
- 通过左下\右上两个点的坐标来设定world坐标系统,并切换到world模式(非world模式会reset).
- 如果已经是world模式,则所有的绘制会在新坐标下重绘.
动画操作
延迟:delay
turtle.delay(delay=None)
Parameters: delay – positive integer
快速绘图:tracer/update
turtle.tracer(n=None, delay=None)
Parameters:
n – nonnegative integer
delay – nonnegative integer
turtle.update()
- tracer:关掉\开启绘图动画.n:每n次屏幕更新显示一次,delay:每次延时.
- update:屏幕更新.
输入操作
弹出文本输入框:textinput
turtle.textinput(title, prompt)
Parameters:
title – string
prompt – string
turtle.numinput(title, prompt, default=None, minval=None, maxval=None)
Parameters:
title – string
prompt – string
default – number (optional)
minval – number (optional)
maxval – number (optional)
模式设定
绘画模式:mode
turtle.mode(mode=None)
Parameters: mode – one of the strings “standard”, “logo” or “world”
| Mode |
Initial turtle heading |
positive angles |
| “standard” |
to the right (east) |
counterclockwise |
| “logo” |
upward (north) |
clockwise |
颜色模式:colormode
turtle.colormode(cmode=None)
Parameters: cmode – one of the values 1.0 or 255
查询画布:getcanvas
turtle.getcanvas()
查询图形:getshapes
turtle.getshapes()
注册新图形:register_shape/addshape
turtle.register_shape(name, shape=None)
turtle.addshape(name, shape=None)
查询海龟:turtles
turtle.turtles()
查询屏幕尺寸:window_height/window_width
turtle.window_height()
turtle.window_width()
屏幕特有操作(非继承自TurtleScreen)
关闭海龟绘图窗口:bye
turtle.bye()
点击鼠标后关闭:exitonclick
turtle.exitonclick()
屏幕设定:setup
turtle.setup(width=_CFG["width"], height=_CFG["height"], startx=_CFG["leftright"], starty=_CFG["topbottom"])
Parameters:
width – if an integer, a size in pixels, if a float, a fraction of the screen; default is 50% of screen
height – if an integer, the height in pixels, if a float, a fraction of the screen; default is 75% of screen
startx – if positive, starting position in pixels from the left edge of the screen, if negative from the right edge, if None, center window horizontally
starty – if positive, starting position in pixels from the top edge of the screen, if negative from the bottom edge, if None, center window vertically
屏幕标题:title
turtle.title(titlestring)
Parameters: titlestring – a string that is shown in the titlebar of the turtle graphics window
公共类
造龟:RawTurtle/RawPen
class turtle.RawTurtle(canvas)
class turtle.RawPen(canvas)
Parameters: canvas – a tkinter.Canvas, a ScrolledCanvas or a TurtleScreen
默认造龟:Turtle
class turtle.Turtle
海龟屏:TurtleScreen
class turtle.TurtleScreen(cv)
Parameters: cv – a tkinter.Canvas
屏幕:Screen
class turtle.Screen
- 海龟屏的子类,添加了上一节里的新功能(bye/title等)
class turtle.ScrolledCanvas(master)
Parameters: master – some Tkinter widget to contain the ScrolledCanvas, i.e. a Tkinter-canvas with scrollbars added
Used by class Screen, which thus automatically provides a ScrolledCanvas as playground for the turtles.
图形类:Shape
class turtle.Shape(type_, data)
Parameters: type_ – one of the strings “polygon”, “image”, “compound”
Shape.addcomponent(poly, fill, outline=None)
Parameters:
poly – a polygon, i.e. a tuple of pairs of numbers
fill – a color the poly will be filled with
outline – a color for the poly’s outline (if given)
| type_ |
data |
| “polygon” |
a polygon-tuple, i.e. a tuple of pairs of coordinates |
| “image” |
an image (in this form only used internally!) |
| “compound” |
None (a compound shape has to be constructed using the addcomponent() method) |
向量:Vec2D
class turtle.Vec2D(x, y)
a + b vector addition
a - b vector subtraction
a * b inner product
k * a and a * k multiplication with scalar
abs(a) absolute value of a
a.rotate(angle) rotation
转换语言:write_docstringdict
turtle.write_docstringdict(filename="turtle_docstringdict")
Parameters: filename – a string, used as filename
Create and write docstring-dictionary to a Python script with the given filename. This function has to be called explicitly (it is not used by the turtle graphics classes). The docstring dictionary will be written to the Python script filename.py. It is intended to serve as a template for translation of the docstrings into different languages.
turtle配置文件
- 可以建一个turtle.cfg,每次import的时候会自动导入.
- cfg样式:
width = 0.5
height = 0.75
leftright = None
topbottom = None
canvwidth = 400
canvheight = 300
mode = standard
colormode = 1.0
delay = 10
undobuffersize = 1000
shape = classic
pencolor = black
fillcolor = black
resizemode = noresize
visible = True
language = english
exampleturtle = turtle
examplescreen = screen
title = Python Turtle Graphics
using_IDLE = False
- 前四行用于Screen.setup()
- 5/6行用于Screen.screensize()
- shape 可以是任意内建图形.
- fillcolor 用于填充颜色.
- Lib/turtledemo目录下有一个turtle.cfg可以用来参考学习.
漂亮的turtledemo
- 用
python -m turtledemo可以开启演示demo的总控台.
- 用
python -m turtledemo.demo名称可以直接打开对应的演示demo
| Name |
Description |
Features |
| bytedesign |
complex classical turtle graphics pattern |
tracer(), delay, update() |
| chaos |
graphs Verhulst dynamics, shows that computer’s computations can generate results sometimes against the common sense expectations |
world coordinates |
| clock |
analog clock showing time of your computer |
turtles as clock’s hands, ontimer |
| colormixer |
experiment with r, g, b |
ondrag() |
| forest |
3 breadth-first trees |
randomization |
| fractalcurves |
Hilbert & Koch curves |
recursion |
| lindenmayer |
ethnomathematics (indian kolams) |
L-System |
| minimal_hanoi |
Towers of Hanoi |
Rectangular Turtles as Hanoi discs (shape, shapesize) |
| nim |
play the classical nim game with three heaps of sticks against the computer. |
turtles as nimsticks, event driven (mouse, keyboard) |
| paint |
super minimalistic drawing program |
onclick() |
| peace |
elementary |
turtle: appearance and animation |
| penrose |
aperiodic tiling with kites and darts |
stamp() |
| planet_and_moon |
simulation of gravitational system |
compound shapes, Vec2D |
| round_dance |
dancing turtles rotating pairwise in opposite direction |
compound shapes, clone shapesize, tilt, get_shapepoly, update |
| sorting_animate |
visual demonstration of different sorting methods |
simple alignment, randomization |
| tree |
a (graphical) breadth first tree (using generators) |
clone() |
| two_canvases |
simple design |
turtles on two canvases |
| wikipedia |
a pattern from the wikipedia article on turtle graphics |
clone(), undo() |
| yinyang |
another elementary example |
circle() |
