Patch #3064: Port new turtle module and demos to 3.0.
diff --git a/Doc/library/tkinter.turtle.rst b/Doc/library/tkinter.turtle.rst
index d91ac8e..575c2fc 100644
--- a/Doc/library/tkinter.turtle.rst
+++ b/Doc/library/tkinter.turtle.rst
@@ -1,288 +1,1887 @@
-:mod:`tkinter.turtle` --- Turtle graphics for Tk
-================================================
+========================================
+:mod:`turtle` --- Turtle graphics for Tk
+========================================
-.. module:: tkinter.turtle
- :platform: Tk
- :synopsis: An environment for turtle graphics.
-.. moduleauthor:: Guido van Rossum <guido@python.org>
+Introduction
+============
+
+Turtle graphics is a popular way for introducing programming to kids. It was
+part of the original Logo programming language developed by Wally Feurzig and
+Seymour Papert in 1966.
+
+Imagine a robotic turtle starting at (0, 0) in the x-y plane. Give it the
+command ``turtle.forward(15)``, and it moves (on-screen!) 15 pixels in the
+direction it is facing, drawing a line as it moves. Give it the command
+``turtle.left(25)``, and it rotates in-place 25 degrees clockwise.
+
+By combining together these and similar commands, intricate shapes and pictures
+can easily be drawn.
+
+The :mod:`turtle` module is an extended reimplementation of the same-named
+module from the Python standard distribution up to version Python 2.5.
+
+It tries to keep the merits of the old turtle module and to be (nearly) 100%
+compatible with it. This means in the first place to enable the learning
+programmer to use all the commands, classes and methods interactively when using
+the module from within IDLE run with the ``-n`` switch.
+
+The turtle module provides turtle graphics primitives, in both object-oriented
+and procedure-oriented ways. Because it uses :mod:`Tkinter` for the underlying
+graphics, it needs a version of python installed with Tk support.
+
+The object-oriented interface uses essentially two+two classes:
+
+1. The :class:`TurtleScreen` class defines graphics windows as a playground for
+ the drawing turtles. Its constructor needs a :class:`Tkinter.Canvas` or a
+ :class:`ScrolledCanvas` as argument. It should be used when :mod:`turtle` is
+ used as part of some application.
+
+ Derived from :class:`TurtleScreen` is the subclass :class:`Screen`. Screen
+ is implemented as sort of singleton, so there can exist only one instance of
+ Screen at a time. It should be used when :mod:`turtle` is used as a
+ standalone tool for doing graphics.
+
+ All methods of TurtleScreen/Screen also exist as functions, i.e. as part of
+ the procedure-oriented interface.
+
+2. :class:`RawTurtle` (alias: :class:`RawPen`) defines Turtle objects which draw
+ on a :class:`TurtleScreen`. Its constructor needs a Canvas, ScrolledCanvas
+ or TurtleScreen as argument, so the RawTurtle objects know where to draw.
+
+ Derived from RawTurtle is the subclass :class:`Turtle` (alias: :class:`Pen`),
+ which draws on "the" :class:`Screen` - instance which is automatically
+ created, if not already present.
+
+ All methods of RawTurtle/Turtle also exist as functions, i.e. part of the
+ procedure-oriented interface.
+
+The procedural interface provides functions which are derived from the methods
+of the classes :class:`Screen` and :class:`Turtle`. They have the same names as
+the corresponding methods. A screen object is automativally created whenever a
+function derived from a Screen method is called. An (unnamed) turtle object is
+automatically created whenever any of the functions derived from a Turtle method
+is called.
+
+To use multiple turtles an a screen one has to use the object-oriented interface.
+
+.. note::
+ In the following documentation the argument list for functions is given.
+ Methods, of course, have the additional first argument *self* which is
+ omitted here.
-.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+Overview over available Turtle and Screen methods
+=================================================
+
+Turtle methods
+--------------
+
+Turtle motion
+ Move and draw
+ | :func:`forward` | :func:`fd`
+ | :func:`backward` | :func:`bk` | :func:`back`
+ | :func:`right` | :func:`rt`
+ | :func:`left` | :func:`lt`
+ | :func:`goto` | :func:`setpos` | :func:`setposition`
+ | :func:`setx`
+ | :func:`sety`
+ | :func:`setheading` | :func:`seth`
+ | :func:`home`
+ | :func:`circle`
+ | :func:`dot`
+ | :func:`stamp`
+ | :func:`clearstamp`
+ | :func:`clearstamps`
+ | :func:`undo`
+ | :func:`speed`
+
+ Tell Turtle's state
+ | :func:`position` | :func:`pos`
+ | :func:`towards`
+ | :func:`xcor`
+ | :func:`ycor`
+ | :func:`heading`
+ | :func:`distance`
+
+ Setting and measurement
+ | :func:`degrees`
+ | :func:`radians`
+
+Pen control
+ Drawing state
+ | :func:`pendown` | :func:`pd` | :func:`down`
+ | :func:`penup` | :func:`pu` | :func:`up`
+ | :func:`pensize` | :func:`width`
+ | :func:`pen`
+ | :func:`isdown`
+
+ Color control
+ | :func:`color`
+ | :func:`pencolor`
+ | :func:`fillcolor`
+
+ Filling
+ | :func:`filling`
+ | :func:`begin_fill`
+ | :func:`end_fill`
+
+ More drawing control
+ | :func:`reset`
+ | :func:`clear`
+ | :func:`write`
+
+Turtle state
+ Visibility
+ | :func:`showturtle` | :func:`st`
+ | :func:`hideturtle` | :func:`ht`
+ | :func:`isvisible`
+
+ Appearance
+ | :func:`shape`
+ | :func:`resizemode`
+ | :func:`shapesize` | :func:`turtlesize`
+ | :func:`settiltangle`
+ | :func:`tiltangle`
+ | :func:`tilt`
+
+Using events
+ | :func:`onclick`
+ | :func:`onrelease`
+ | :func:`ondrag`
+
+Special Turtle methods
+ | :func:`begin_poly`
+ | :func:`end_poly`
+ | :func:`get_poly`
+ | :func:`clone`
+ | :func:`getturtle` | :func:`getpen`
+ | :func:`getscreen`
+ | :func:`setundobuffer`
+ | :func:`undobufferentries`
-The :mod:`tkinter.turtle` module provides turtle graphics primitives, in both an
-object-oriented and procedure-oriented ways. Because it uses :mod:`tkinter` for
-the underlying graphics, it needs a version of python installed with Tk support.
+Methods of TurtleScreen/Screen
+------------------------------
-The procedural interface uses a pen and a canvas which are automagically created
-when any of the functions are called.
+Window control
+ | :func:`bgcolor`
+ | :func:`bgpic`
+ | :func:`clear` | :func:`clearscreen`
+ | :func:`reset` | :func:`resetscreen`
+ | :func:`screensize`
+ | :func:`setworldcoordinates`
-The :mod:`tkinter.turtle` module defines the following functions:
+Animation control
+ | :func:`delay`
+ | :func:`tracer`
+ | :func:`update`
+
+Using screen events
+ | :func:`listen`
+ | :func:`onkey`
+ | :func:`onclick` | :func:`onscreenclick`
+ | :func:`ontimer`
+
+Settings and special methods
+ | :func:`mode`
+ | :func:`colormode`
+ | :func:`getcanvas`
+ | :func:`getshapes`
+ | :func:`register_shape` | :func:`addshape`
+ | :func:`turtles`
+ | :func:`window_height`
+ | :func:`window_width`
+
+Methods specific to Screen
+ | :func:`bye`
+ | :func:`exitonclick`
+ | :func:`setup`
+ | :func:`title`
-.. function:: degrees()
+Methods of RawTurtle/Turtle and corresponding functions
+=======================================================
- Set angle measurement units to degrees.
+Most of the examples in this section refer to a Turtle instance called
+``turtle``.
-
-.. function:: radians()
-
- Set angle measurement units to radians.
-
-
-.. function:: setup(**kwargs)
-
- Sets the size and position of the main window. Keywords are:
-
- * ``width``: either a size in pixels or a fraction of the screen. The default is
- 50% of the screen.
-
- * ``height``: either a size in pixels or a fraction of the screen. The default
- is 50% of the screen.
-
- * ``startx``: starting position in pixels from the left edge of the screen.
- ``None`` is the default value and centers the window horizontally on screen.
-
- * ``starty``: starting position in pixels from the top edge of the screen.
- ``None`` is the default value and centers the window vertically on screen.
-
- Examples::
-
- # Uses default geometry: 50% x 50% of screen, centered.
- setup()
-
- # Sets window to 200x200 pixels, in upper left of screen
- setup (width=200, height=200, startx=0, starty=0)
-
- # Sets window to 75% of screen by 50% of screen, and centers it.
- setup(width=.75, height=0.5, startx=None, starty=None)
-
-
-.. function:: title(title_str)
-
- Set the window's title to *title*.
-
-
-.. function:: done()
-
- Enters the Tk main loop. The window will continue to be displayed until the
- user closes it or the process is killed.
-
-
-.. function:: reset()
-
- Clear the screen, re-center the pen, and set variables to the default values.
-
-
-.. function:: clear()
-
- Clear the screen.
-
-
-.. function:: tracer(flag)
-
- Set tracing on/off (according to whether flag is true or not). Tracing means
- line are drawn more slowly, with an animation of an arrow along the line.
-
-
-.. function:: speed(speed)
-
- Set the speed of the turtle. Valid values for the parameter *speed* are
- ``'fastest'`` (no delay), ``'fast'``, (delay 5ms), ``'normal'`` (delay 10ms),
- ``'slow'`` (delay 15ms), and ``'slowest'`` (delay 20ms).
-
-
-.. function:: delay(delay)
-
- Set the speed of the turtle to *delay*, which is given in ms.
-
+Turtle motion
+-------------
.. function:: forward(distance)
+ fd(distance)
- Go forward *distance* steps.
+ :param distance: a number (integer or float)
+
+ Move the turtle forward by the specified *distance*, in the direction the
+ turtle is headed.
+
+ >>> turtle.position()
+ (0.00, 0.00)
+ >>> turtle.forward(25)
+ >>> turtle.position()
+ (25.00,0.00)
+ >>> turtle.forward(-75)
+ >>> turtle.position()
+ (-50.00,0.00)
-.. function:: backward(distance)
+.. function:: back(distance)
+ bk(distance)
+ backward(distance)
- Go backward *distance* steps.
+ :param distance: a number
+ Move the turtle backward by *distance*, opposite to the direction the
+ turtle is headed. Do not change the turtle's heading.
-.. function:: left(angle)
-
- Turn left *angle* units. Units are by default degrees, but can be set via the
- :func:`degrees` and :func:`radians` functions.
+ >>> turtle.position()
+ (0.00, 0.00)
+ >>> turtle.backward(30)
+ >>> turtle.position()
+ (-30.00, 0.00)
.. function:: right(angle)
+ rt(angle)
- Turn right *angle* units. Units are by default degrees, but can be set via the
- :func:`degrees` and :func:`radians` functions.
+ :param angle: a number (integer or float)
+
+ Turn turtle right by *angle* units. (Units are by default degrees, but
+ can be set via the :func:`degrees` and :func:`radians` functions.) Angle
+ orientation depends on the turtle mode, see :func:`mode`.
+
+ >>> turtle.heading()
+ 22.0
+ >>> turtle.right(45)
+ >>> turtle.heading()
+ 337.0
-.. function:: up()
+.. function:: left(angle)
+ lt(angle)
- Move the pen up --- stop drawing.
+ :param angle: a number (integer or float)
+ Turn turtle left by *angle* units. (Units are by default degrees, but
+ can be set via the :func:`degrees` and :func:`radians` functions.) Angle
+ orientation depends on the turtle mode, see :func:`mode`.
-.. function:: down()
+ >>> turtle.heading()
+ 22.0
+ >>> turtle.left(45)
+ >>> turtle.heading()
+ 67.0
- Move the pen down --- draw when moving.
+.. function:: goto(x, y=None)
+ setpos(x, y=None)
+ setposition(x, y=None)
+ :param x: a number or a pair/vector of numbers
+ :param y: a number or ``None``
-.. function:: width(width)
+ If *y* is ``None``, *x* must be a pair of coordinates or a :class:`Vec2D`
+ (e.g. as returned by :func:`pos`).
- Set the line width to *width*.
+ Move turtle to an absolute position. If the pen is down, draw line. Do
+ not change the turtle's orientation.
-
-.. function:: color(s)
- color((r, g, b))
- color(r, g, b)
-
- Set the pen color. In the first form, the color is specified as a Tk color
- specification as a string. The second form specifies the color as a tuple of
- the RGB values, each in the range [0..1]. For the third form, the color is
- specified giving the RGB values as three separate parameters (each in the range
- [0..1]).
-
-
-.. function:: write(text[, move])
-
- Write *text* at the current pen position. If *move* is true, the pen is moved to
- the bottom-right corner of the text. By default, *move* is false.
-
-
-.. function:: fill(flag)
-
- The complete specifications are rather complex, but the recommended usage is:
- call ``fill(1)`` before drawing a path you want to fill, and call ``fill(0)``
- when you finish to draw the path.
-
-
-.. function:: begin_fill()
-
- Switch turtle into filling mode; Must eventually be followed by a corresponding
- end_fill() call. Otherwise it will be ignored.
-
-
-.. function:: end_fill()
-
- End filling mode, and fill the shape; equivalent to ``fill(0)``.
-
-
-.. function:: circle(radius[, extent])
-
- Draw a circle with radius *radius* whose center-point is *radius* units left of
- the turtle. *extent* determines which part of a circle is drawn: if not given it
- defaults to a full circle.
-
- If *extent* is not a full circle, one endpoint of the arc is the current pen
- position. The arc is drawn in a counter clockwise direction if *radius* is
- positive, otherwise in a clockwise direction. In the process, the direction of
- the turtle is changed by the amount of the *extent*.
-
-
-.. function:: goto(x, y)
- goto((x, y))
-
- Go to co-ordinates *x*, *y*. The co-ordinates may be specified either as two
- separate arguments or as a 2-tuple.
-
-
-.. function:: towards(x, y)
-
- Return the angle of the line from the turtle's position to the point *x*, *y*.
- The co-ordinates may be specified either as two separate arguments, as a
- 2-tuple, or as another pen object.
-
-
-.. function:: heading()
-
- Return the current orientation of the turtle.
-
-
-.. function:: setheading(angle)
-
- Set the orientation of the turtle to *angle*.
-
-
-.. function:: position()
-
- Return the current location of the turtle as an ``(x,y)`` pair.
+ >>> tp = turtle.pos()
+ >>> tp
+ (0.00, 0.00)
+ >>> turtle.setpos(60,30)
+ >>> turtle.pos()
+ (60.00,30.00)
+ >>> turtle.setpos((20,80))
+ >>> turtle.pos()
+ (20.00,80.00)
+ >>> turtle.setpos(tp)
+ >>> turtle.pos()
+ (0.00,0.00)
.. function:: setx(x)
- Set the x coordinate of the turtle to *x*.
+ :param x: a number (integer or float)
+
+ Set the turtle's first coordinate to *x*, leave second coordinate
+ unchanged.
+
+ >>> turtle.position()
+ (0.00, 240.00)
+ >>> turtle.setx(10)
+ >>> turtle.position()
+ (10.00, 240.00)
.. function:: sety(y)
- Set the y coordinate of the turtle to *y*.
+ :param y: a number (integer or float)
+
+ Set the turtle's first coordinate to *y*, leave second coordinate
+ unchanged.
+
+ >>> turtle.position()
+ (0.00, 40.00)
+ >>> turtle.sety(-10)
+ >>> turtle.position()
+ (0.00, -10.00)
-.. function:: window_width()
+.. function:: setheading(to_angle)
+ seth(to_angle)
- Return the width of the canvas window.
+ :param to_angle: a number (integer or float)
+
+ Set the orientation of the turtle to *to_angle*. Here are some common
+ directions in degrees:
+
+ =================== ====================
+ standard mode logo mode
+ =================== ====================
+ 0 - east 0 - north
+ 90 - north 90 - east
+ 180 - west 180 - south
+ 270 - south 270 - west
+ =================== ====================
+
+ >>> turtle.setheading(90)
+ >>> turtle.heading()
+ 90
+
+
+.. function:: home()
+
+ Move turtle to the origin -- coordinates (0,0) -- and set its heading to
+ its start-orientation (which depends on the mode, see :func:`mode`).
+
+
+.. function:: circle(radius, extent=None, steps=None)
+
+ :param radius: a number
+ :param extent: a number (or ``None``)
+ :param steps: an integer (or ``None``)
+
+ Draw a circle with given *radius*. The center is *radius* units left of
+ the turtle; *extent* -- an angle -- determines which part of the circle
+ is drawn. If *extent* is not given, draw the entire circle. If *extent*
+ is not a full circle, one endpoint of the arc is the current pen
+ position. Draw the arc in counterclockwise direction if *radius* is
+ positive, otherwise in clockwise direction. Finally the direction of the
+ turtle is changed by the amount of *extent*.
+
+ As the circle is approximated by an inscribed regular polygon, *steps*
+ determines the number of steps to use. If not given, it will be
+ calculated automatically. May be used to draw regular polygons.
+
+ >>> turtle.circle(50)
+ >>> turtle.circle(120, 180) # draw a semicircle
+
+
+.. function:: dot(size=None, *color)
+
+ :param size: an integer >= 1 (if given)
+ :param color: a colorstring or a numeric color tuple
+
+ Draw a circular dot with diameter *size*, using *color*. If *size* is
+ not given, the maximum of pensize+4 and 2*pensize is used.
+
+ >>> turtle.dot()
+ >>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50)
+
+
+.. function:: stamp()
+
+ Stamp a copy of the turtle shape onto the canvas at the current turtle
+ position. Return a stamp_id for that stamp, which can be used to delete
+ it by calling ``clearstamp(stamp_id)``.
+
+ >>> turtle.color("blue")
+ >>> turtle.stamp()
+ 13
+ >>> turtle.fd(50)
+
+
+.. function:: clearstamp(stampid)
+
+ :param stampid: an integer, must be return value of previous
+ :func:`stamp` call
+
+ Delete stamp with given *stampid*.
+
+ >>> turtle.color("blue")
+ >>> astamp = turtle.stamp()
+ >>> turtle.fd(50)
+ >>> turtle.clearstamp(astamp)
+
+
+.. function:: clearstamps(n=None)
+
+ :param n: an integer (or ``None``)
+
+ Delete all or first/last *n* of turtle's stamps. If *n* is None, delete
+ all stamps, if *n* > 0 delete first *n* stamps, else if *n* < 0 delete
+ last *n* stamps.
+
+ >>> for i in range(8):
+ ... turtle.stamp(); turtle.fd(30)
+ >>> turtle.clearstamps(2)
+ >>> turtle.clearstamps(-2)
+ >>> turtle.clearstamps()
+
+
+.. function:: undo()
+
+ Undo (repeatedly) the last turtle action(s). Number of available
+ undo actions is determined by the size of the undobuffer.
+
+ >>> for i in range(4):
+ ... turtle.fd(50); turtle.lt(80)
+ ...
+ >>> for i in range(8):
+ ... turtle.undo()
+
+
+.. function:: speed(speed=None)
+
+ :param speed: an integer in the range 0..10 or a speedstring (see below)
+
+ Set the turtle's speed to an integer value in the range 0..10. If no
+ argument is given, return current speed.
+
+ If input is a number greater than 10 or smaller than 0.5, speed is set
+ to 0. Speedstrings are mapped to speedvalues as follows:
+
+ * "fastest": 0
+ * "fast": 10
+ * "normal": 6
+ * "slow": 3
+ * "slowest": 1
+
+ Speeds from 1 to 10 enforce increasingly faster animation of line drawing
+ and turtle turning.
+
+ Attention: *speed* = 0 means that *no* animation takes
+ place. forward/back makes turtle jump and likewise left/right make the
+ turtle turn instantly.
+
+ >>> turtle.speed(3)
+
+
+Tell Turtle's state
+-------------------
+
+.. function:: position()
+ pos()
+
+ Return the turtle's current location (x,y) (as a :class:`Vec2D` vector).
+
+ >>> turtle.pos()
+ (0.00, 240.00)
+
+
+.. function:: towards(x, y=None)
+
+ :param x: a number or a pair/vector of numbers or a turtle instance
+ :param y: a number if *x* is a number, else ``None``
+
+ Return the angle between the line from turtle position to position specified
+ by (x,y), the vector or the other turtle. This depends on the turtle's start
+ orientation which depends on the mode - "standard"/"world" or "logo").
+
+ >>> turtle.pos()
+ (10.00, 10.00)
+ >>> turtle.towards(0,0)
+ 225.0
+
+
+.. function:: xcor()
+
+ Return the turtle's x coordinate.
+
+ >>> reset()
+ >>> turtle.left(60)
+ >>> turtle.forward(100)
+ >>> print turtle.xcor()
+ 50.0
+
+
+.. function:: ycor()
+
+ Return the turtle's y coordinate.
+
+ >>> reset()
+ >>> turtle.left(60)
+ >>> turtle.forward(100)
+ >>> print turtle.ycor()
+ 86.6025403784
+
+
+.. function:: heading()
+
+ Return the turtle's current heading (value depends on the turtle mode, see
+ :func:`mode`).
+
+ >>> turtle.left(67)
+ >>> turtle.heading()
+ 67.0
+
+
+.. function:: distance(x, y=None)
+
+ :param x: a number or a pair/vector of numbers or a turtle instance
+ :param y: a number if *x* is a number, else ``None``
+
+ Return the distance from the turtle to (x,y), the given vector, or the given
+ other turtle, in turtle step units.
+
+ >>> turtle.pos()
+ (0.00, 0.00)
+ >>> turtle.distance(30,40)
+ 50.0
+ >>> joe = Turtle()
+ >>> joe.forward(77)
+ >>> turtle.distance(joe)
+ 77.0
+
+
+Settings for measurement
+------------------------
+
+.. function:: degrees(fullcircle=360.0)
+
+ :param fullcircle: a number
+
+ Set angle measurement units, i.e. set number of "degrees" for a full circle.
+ Default value is 360 degrees.
+
+ >>> turtle.left(90)
+ >>> turtle.heading()
+ 90
+ >>> turtle.degrees(400.0) # angle measurement in gon
+ >>> turtle.heading()
+ 100
+
+
+.. function:: radians()
+
+ Set the angle measurement units to radians. Equivalent to
+ ``degrees(2*math.pi)``.
+
+ >>> turtle.heading()
+ 90
+ >>> turtle.radians()
+ >>> turtle.heading()
+ 1.5707963267948966
+
+
+Pen control
+-----------
+
+Drawing state
+~~~~~~~~~~~~~
+
+.. function:: pendown()
+ pd()
+ down()
+
+ Pull the pen down -- drawing when moving.
+
+
+.. function:: penup()
+ pu()
+ up()
+
+ Pull the pen up -- no drawing when moving.
+
+
+.. function:: pensize(width=None)
+ width(width=None)
+
+ :param width: a positive number
+
+ Set the line thickness to *width* or return it. If resizemode is set to
+ "auto" and turtleshape is a polygon, that polygon is drawn with the same line
+ thickness. If no argument is given, the current pensize is returned.
+
+ >>> turtle.pensize()
+ 1
+ >>> turtle.pensize(10) # from here on lines of width 10 are drawn
+
+
+.. function:: pen(pen=None, **pendict)
+
+ :param pen: a dictionary with some or all of the below listed keys
+ :param pendict: one or more keyword-arguments with the below listed keys as keywords
+
+ Return or set the pen's attributes in a "pen-dictionary" with the following
+ key/value pairs:
+
+ * "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
+
+ This dicionary can be used as argument for a subsequent call to :func:`pen`
+ to restore the former pen-state. Moreover one or more of these attributes
+ can be provided as keyword-arguments. This can be used to set several pen
+ attributes in one statement.
+
+ >>> turtle.pen(fillcolor="black", pencolor="red", pensize=10)
+ >>> turtle.pen()
+ {'pensize': 10, 'shown': True, 'resizemode': 'auto', 'outline': 1,
+ 'pencolor': 'red', 'pendown': True, 'fillcolor': 'black',
+ 'stretchfactor': (1,1), 'speed': 3}
+ >>> penstate=turtle.pen()
+ >>> turtle.color("yellow","")
+ >>> turtle.penup()
+ >>> turtle.pen()
+ {'pensize': 10, 'shown': True, 'resizemode': 'auto', 'outline': 1,
+ 'pencolor': 'yellow', 'pendown': False, 'fillcolor': '',
+ 'stretchfactor': (1,1), 'speed': 3}
+ >>> p.pen(penstate, fillcolor="green")
+ >>> p.pen()
+ {'pensize': 10, 'shown': True, 'resizemode': 'auto', 'outline': 1,
+ 'pencolor': 'red', 'pendown': True, 'fillcolor': 'green',
+ 'stretchfactor': (1,1), 'speed': 3}
+
+
+.. function:: isdown()
+
+ Return ``True`` if pen is down, ``False`` if it's up.
+
+ >>> turtle.penup()
+ >>> turtle.isdown()
+ False
+ >>> turtle.pendown()
+ >>> turtle.isdown()
+ True
+
+
+Color control
+~~~~~~~~~~~~~
+
+.. function:: pencolor(*args)
+
+ Return or set the pencolor.
+
+ Four input formats are allowed:
+
+ ``pencolor()``
+ Return the current pencolor as color specification string, possibly in
+ hex-number format (see example). May be used as input to another
+ color/pencolor/fillcolor call.
+
+ ``pencolor(colorstring)``
+ Set pencolor to *colorstring*, which is a Tk color specification string,
+ such as ``"red"``, ``"yellow"``, or ``"#33cc8c"``.
+
+ ``pencolor((r, g, b))``
+ Set pencolor to the RGB color represented by the tuple of *r*, *g*, and
+ *b*. Each of *r*, *g*, and *b* must be in the range 0..colormode, where
+ colormode is either 1.0 or 255 (see :func:`colormode`).
+
+ ``pencolor(r, g, b)``
+ Set pencolor to the RGB color represented by *r*, *g*, and *b*. Each of
+ *r*, *g*, and *b* must be in the range 0..colormode.
+
+ If turtleshape is a polygon, the outline of that polygon is drawn with the
+ newly set pencolor.
+
+ >>> turtle.pencolor("brown")
+ >>> tup = (0.2, 0.8, 0.55)
+ >>> turtle.pencolor(tup)
+ >>> turtle.pencolor()
+ "#33cc8c"
+
+
+.. function:: fillcolor(*args)
+
+ Return or set the fillcolor.
+
+ Four input formats are allowed:
+
+ ``fillcolor()``
+ Return the current fillcolor as color specification string, possibly in
+ hex-number format (see example). May be used as input to another
+ color/pencolor/fillcolor call.
+
+ ``fillcolor(colorstring)``
+ Set fillcolor to *colorstring*, which is a Tk color specification string,
+ such as ``"red"``, ``"yellow"``, or ``"#33cc8c"``.
+
+ ``fillcolor((r, g, b))``
+ Set fillcolor to the RGB color represented by the tuple of *r*, *g*, and
+ *b*. Each of *r*, *g*, and *b* must be in the range 0..colormode, where
+ colormode is either 1.0 or 255 (see :func:`colormode`).
+
+ ``fillcolor(r, g, b)``
+ Set fillcolor to the RGB color represented by *r*, *g*, and *b*. Each of
+ *r*, *g*, and *b* must be in the range 0..colormode.
+
+ If turtleshape is a polygon, the interior of that polygon is drawn
+ with the newly set fillcolor.
+
+ >>> turtle.fillcolor("violet")
+ >>> col = turtle.pencolor()
+ >>> turtle.fillcolor(col)
+ >>> turtle.fillcolor(0, .5, 0)
+
+
+.. function:: color(*args)
+
+ Return or set pencolor and fillcolor.
+
+ Several input formats are allowed. They use 0 to 3 arguments as
+ follows:
+
+ ``color()``
+ Return the current pencolor and the current fillcolor as a pair of color
+ specification strings as returned by :func:`pencolor` and
+ :func:`fillcolor`.
+
+ ``color(colorstring)``, ``color((r,g,b))``, ``color(r,g,b)``
+ Inputs as in :func:`pencolor`, set both, fillcolor and pencolor, to the
+ given value.
+
+ ``color(colorstring1, colorstring2)``, ``color((r1,g1,b1), (r2,g2,b2))``
+ Equivalent to ``pencolor(colorstring1)`` and ``fillcolor(colorstring2)``
+ and analogously if the other input format is used.
+
+ If turtleshape is a polygon, outline and interior of that polygon is drawn
+ with the newly set colors.
+
+ >>> turtle.color("red", "green")
+ >>> turtle.color()
+ ("red", "green")
+ >>> colormode(255)
+ >>> color((40, 80, 120), (160, 200, 240))
+ >>> color()
+ ("#285078", "#a0c8f0")
+
+
+See also: Screen method :func:`colormode`.
+
+
+Filling
+~~~~~~~
+
+.. function:: filling()
+
+ Return fillstate (``True`` if filling, ``False`` else).
+
+ >>> turtle.begin_fill()
+ >>> if turtle.filling():
+ ... turtle.pensize(5)
+ else:
+ ... turtle.pensize(3)
+
+
+.. function:: begin_fill()
+
+ To be called just before drawing a shape to be filled.
+
+ >>> turtle.color("black", "red")
+ >>> turtle.begin_fill()
+ >>> turtle.circle(60)
+ >>> turtle.end_fill()
+
+
+.. function:: end_fill()
+
+ Fill the shape drawn after the last call to :func:`begin_fill`.
+
+
+More drawing control
+~~~~~~~~~~~~~~~~~~~~
+
+.. function:: reset()
+
+ Delete the turtle's drawings from the screen, re-center the turtle and set
+ variables to the default values.
+
+ >>> turtle.position()
+ (0.00,-22.00)
+ >>> turtle.heading()
+ 100.0
+ >>> turtle.reset()
+ >>> turtle.position()
+ (0.00,0.00)
+ >>> turtle.heading()
+ 0.0
+
+
+.. function:: clear()
+
+ Delete the turtle's drawings from the screen. Do not move turtle. State and
+ position of the turtle as well as drawings of other turtles are not affected.
+
+
+.. function:: write(arg, move=False, align="left", font=("Arial", 8, "normal"))
+
+ :param arg: object to be written to the TurtleScreen
+ :param move: True/False
+ :param align: one of the strings "left", "center" or right"
+ :param font: a triple (fontname, fontsize, fonttype)
+
+ Write text - the string representation of *arg* - at the current turtle
+ position according to *align* ("left", "center" or right") and with the given
+ font. If *move* is True, the pen is moved to the bottom-right corner of the
+ text. By default, *move* is False.
+
+ >>> turtle.write("Home = ", True, align="center")
+ >>> turtle.write((0,0), True)
+
+
+Turtle state
+------------
+
+Visibility
+~~~~~~~~~~
+
+.. function:: showturtle()
+ st()
+
+ Make the turtle visible.
+
+ >>> turtle.hideturtle()
+ >>> turtle.showturtle()
+
+
+.. function:: hideturtle()
+ ht()
+
+ Make the turtle invisible. It's a good idea to do this while you're in the
+ middle of doing some complex drawing, because hiding the turtle speeds up the
+ drawing observably.
+
+ >>> turtle.hideturtle()
+
+
+.. function:: isvisible()
+
+ Return True if the Turtle is shown, False if it's hidden.
+
+ >>> turtle.hideturtle()
+ >>> print turtle.isvisible():
+ False
+
+
+Appearance
+~~~~~~~~~~
+
+.. function:: shape(name=None)
+
+ :param name: a string which is a valid shapename
+
+ Set turtle shape to shape with given *name* or, if name is not given, return
+ name of current shape. Shape with *name* must exist in the TurtleScreen's
+ shape dictionary. Initially there are the following polygon shapes: "arrow",
+ "turtle", "circle", "square", "triangle", "classic". To learn about how to
+ deal with shapes see Screen method :func:`register_shape`.
+
+ >>> turtle.shape()
+ "arrow"
+ >>> turtle.shape("turtle")
+ >>> turtle.shape()
+ "turtle"
+
+
+.. function:: resizemode(rmode=None)
+
+ :param rmode: one of the strings "auto", "user", "noresize"
+
+ Set resizemode to one of the values: "auto", "user", "noresize". If *rmode*
+ is not given, return current resizemode. Different resizemodes have the
+ following effects:
+
+ - "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
+ :func:`shapesize`.
+ - "noresize": no adaption of the turtle's appearance takes place.
+
+ resizemode("user") is called by :func:`shapesize` when used with arguments.
+
+ >>> turtle.resizemode("noresize")
+ >>> turtle.resizemode()
+ "noresize"
+
+
+.. function:: shapesize(stretch_wid=None, stretch_len=None, outline=None)
+
+ :param stretch_wid: positive number
+ :param stretch_len: positive number
+ :param outline: positive number
+
+ Return or set the pen's attributes x/y-stretchfactors and/or outline. Set
+ resizemode to "user". If and only if resizemode is set to "user", the turtle
+ will be displayed stretched according to its stretchfactors: *stretch_wid* is
+ stretchfactor perpendicular to its orientation, *stretch_len* is
+ stretchfactor in direction of its orientation, *outline* determines the width
+ of the shapes's outline.
+
+ >>> turtle.resizemode("user")
+ >>> turtle.shapesize(5, 5, 12)
+ >>> turtle.shapesize(outline=8)
+
+
+.. function:: tilt(angle)
+
+ :param angle: a number
+
+ Rotate the turtleshape by *angle* from its current tilt-angle, but do *not*
+ change the turtle's heading (direction of movement).
+
+ >>> turtle.shape("circle")
+ >>> turtle.shapesize(5,2)
+ >>> turtle.tilt(30)
+ >>> turtle.fd(50)
+ >>> turtle.tilt(30)
+ >>> turtle.fd(50)
+
+
+.. function:: settiltangle(angle)
+
+ :param angle: a number
+
+ Rotate the turtleshape to point in the direction specified by *angle*,
+ regardless of its current tilt-angle. *Do not* change the turtle's heading
+ (direction of movement).
+
+ >>> turtle.shape("circle")
+ >>> turtle.shapesize(5,2)
+ >>> turtle.settiltangle(45)
+ >>> stamp()
+ >>> turtle.fd(50)
+ >>> turtle.settiltangle(-45)
+ >>> stamp()
+ >>> turtle.fd(50)
+
+
+.. function:: tiltangle()
+
+ Return the current tilt-angle, i.e. the angle between the orientation of the
+ turtleshape and the heading of the turtle (its direction of movement).
+
+ >>> turtle.shape("circle")
+ >>> turtle.shapesize(5,2)
+ >>> turtle.tilt(45)
+ >>> turtle.tiltangle()
+ 45
+
+
+Using events
+------------
+
+.. function:: onclick(fun, btn=1, add=None)
+
+ :param fun: a function with two arguments which will be called with the
+ coordinates of the clicked point on the canvas
+ :param num: number of the mouse-button, defaults to 1 (left mouse button)
+ :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
+ added, otherwise it will replace a former binding
+
+ Bind *fun* to mouse-click events on this turtle. If *fun* is ``None``,
+ existing bindings are removed. Example for the anonymous turtle, i.e. the
+ procedural way:
+
+ >>> def turn(x, y):
+ ... left(180)
+ ...
+ >>> onclick(turn) # Now clicking into the turtle will turn it.
+ >>> onclick(None) # event-binding will be removed
+
+
+.. function:: onrelease(fun, btn=1, add=None)
+
+ :param fun: a function with two arguments which will be called with the
+ coordinates of the clicked point on the canvas
+ :param num: number of the mouse-button, defaults to 1 (left mouse button)
+ :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
+ added, otherwise it will replace a former binding
+
+ Bind *fun* to mouse-button-release events on this turtle. If *fun* is
+ ``None``, existing bindings are removed.
+
+ >>> class MyTurtle(Turtle):
+ ... def glow(self,x,y):
+ ... self.fillcolor("red")
+ ... def unglow(self,x,y):
+ ... self.fillcolor("")
+ ...
+ >>> turtle = MyTurtle()
+ >>> turtle.onclick(turtle.glow) # clicking on turtle turns fillcolor red,
+ >>> turtle.onrelease(turtle.unglow) # releasing turns it to transparent.
+
+
+.. function:: ondrag(fun, btn=1, add=None)
+
+ :param fun: a function with two arguments which will be called with the
+ coordinates of the clicked point on the canvas
+ :param num: number of the mouse-button, defaults to 1 (left mouse button)
+ :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
+ added, otherwise it will replace a former binding
+
+ Bind *fun* to mouse-move events on this turtle. If *fun* is ``None``,
+ existing bindings are removed.
+
+ Remark: Every sequence of mouse-move-events on a turtle is preceded by a
+ mouse-click event on that turtle.
+
+ >>> turtle.ondrag(turtle.goto)
+ # Subsequently, clicking and dragging the Turtle will move it across
+ # the screen thereby producing handdrawings (if pen is down).
+
+
+Special Turtle methods
+----------------------
+
+.. function:: begin_poly()
+
+ Start recording the vertices of a polygon. Current turtle position is first
+ vertex of polygon.
+
+
+.. function:: end_poly()
+
+ Stop recording the vertices of a polygon. Current turtle position is last
+ vertex of polygon. This will be connected with the first vertex.
+
+
+.. function:: get_poly()
+
+ Return the last recorded polygon.
+
+ >>> p = turtle.get_poly()
+ >>> turtle.register_shape("myFavouriteShape", p)
+
+
+.. function:: clone()
+
+ Create and return a clone of the turtle with same position, heading and
+ turtle properties.
+
+ >>> mick = Turtle()
+ >>> joe = mick.clone()
+
+
+.. function:: getturtle()
+
+ Return the Turtle object itself. Only reasonable use: as a function to
+ return the "anonymous turtle":
+
+ >>> pet = getturtle()
+ >>> pet.fd(50)
+ >>> pet
+ <turtle.Turtle object at 0x01417350>
+ >>> turtles()
+ [<turtle.Turtle object at 0x01417350>]
+
+
+.. function:: getscreen()
+
+ Return the :class:`TurtleScreen` object the turtle is drawing on.
+ TurtleScreen methods can then be called for that object.
+
+ >>> ts = turtle.getscreen()
+ >>> ts
+ <turtle.Screen object at 0x01417710>
+ >>> ts.bgcolor("pink")
+
+
+.. function:: setundobuffer(size)
+
+ :param size: an integer or ``None``
+
+ Set or disable undobuffer. If *size* is an integer an empty undobuffer of
+ given size is installed. *size* gives the maximum number of turtle actions
+ that can be undone by the :func:`undo` method/function. If *size* is
+ ``None``, the undobuffer is disabled.
+
+ >>> turtle.setundobuffer(42)
+
+
+.. function:: undobufferentries()
+
+ Return number of entries in the undobuffer.
+
+ >>> while undobufferentries():
+ ... undo()
+
+
+.. _compoundshapes:
+
+Excursus about the use of compound shapes
+-----------------------------------------
+
+To use compound turtle shapes, which consist of several polygons of different
+color, you must use the helper class :class:`Shape` explicitly as described
+below:
+
+1. Create an empty Shape object of type "compound".
+2. Add as many components to this object as desired, using the
+ :meth:`addcomponent` method.
+
+ For example:
+
+ >>> s = Shape("compound")
+ >>> poly1 = ((0,0),(10,-5),(0,10),(-10,-5))
+ >>> s.addcomponent(poly1, "red", "blue")
+ >>> poly2 = ((0,0),(10,-5),(-10,-5))
+ >>> s.addcomponent(poly2, "blue", "red")
+
+3. Now add the Shape to the Screen's shapelist and use it:
+
+ >>> register_shape("myshape", s)
+ >>> shape("myshape")
+
+
+.. note::
+
+ The :class:`Shape` class is used internally by the :func:`register_shape`
+ method in different ways. The application programmer has to deal with the
+ Shape class *only* when using compound shapes like shown above!
+
+
+Methods of TurtleScreen/Screen and corresponding functions
+==========================================================
+
+Most of the examples in this section refer to a TurtleScreen instance called
+``screen``.
+
+
+Window control
+--------------
+
+.. function:: bgcolor(*args)
+
+ :param args: a color string or three numbers in the range 0..colormode or a
+ 3-tuple of such numbers
+
+ Set or return background color of the TurtleScreen.
+
+ >>> screen.bgcolor("orange")
+ >>> screen.bgcolor()
+ "orange"
+ >>> screen.bgcolor(0.5,0,0.5)
+ >>> screen.bgcolor()
+ "#800080"
+
+
+.. function:: bgpic(picname=None)
+
+ :param picname: a string, name of a gif-file or ``"nopic"``, or ``None``
+
+ Set background image or return name of current backgroundimage. If *picname*
+ is a filename, set the corresponding image as background. If *picname* is
+ ``"nopic"``, delete background image, if present. If *picname* is ``None``,
+ return the filename of the current backgroundimage.
+
+ >>> screen.bgpic()
+ "nopic"
+ >>> screen.bgpic("landscape.gif")
+ >>> screen.bgpic()
+ "landscape.gif"
+
+
+.. function:: clear()
+ clearscreen()
+
+ Delete all drawings and all turtles from the TurtleScreen. Reset the now
+ empty TurtleScreen to its initial state: white background, no background
+ image, no event bindings and tracing on.
+
+ .. note::
+ This TurtleScreen method is available as a global function only under the
+ name ``clearscreen``. The global function ``clear`` is another one
+ derived from the Turtle method ``clear``.
+
+
+.. function:: reset()
+ resetscreen()
+
+ Reset all Turtles on the Screen to their initial state.
+
+ .. note::
+ This TurtleScreen method is available as a global function only under the
+ name ``resetscreen``. The global function ``reset`` is another one
+ derived from the Turtle method ``reset``.
+
+
+.. function:: screensize(canvwidth=None, canvheight=None, bg=None)
+
+ :param canvwidth: positive integer, new width of canvas in pixels
+ :param canvheight: positive integer, new height of canvas in pixels
+ :param bg: colorstring or color-tupel, new background color
+
+ If no arguments are given, return current (canvaswidth, canvasheight). Else
+ resize the canvas the turtles are drawing on. Do not alter the drawing
+ window. To observe hidden parts of the canvas, use the scrollbars. With this
+ method, one can make visible those parts of a drawing which were outside the
+ canvas before.
+
+ >>> turtle.screensize(2000,1500)
+ # e.g. to search for an erroneously escaped turtle ;-)
+
+
+.. function:: setworldcoordinates(llx, lly, urx, ury)
+
+ :param llx: a number, x-coordinate of lower left corner of canvas
+ :param lly: a number, y-coordinate of lower left corner of canvas
+ :param urx: a number, x-coordinate of upper right corner of canvas
+ :param ury: a number, y-coordinate of upper right corner of canvas
+
+ Set up user-defined coordinate system and switch to mode "world" if
+ necessary. This performs a ``screen.reset()``. If mode "world" is already
+ active, all drawings are redrawn according to the new coordinates.
+
+ **ATTENTION**: in user-defined coordinate systems angles may appear
+ distorted.
+
+ >>> screen.reset()
+ >>> screen.setworldcoordinates(-50,-7.5,50,7.5)
+ >>> for _ in range(72):
+ ... left(10)
+ ...
+ >>> for _ in range(8):
+ ... left(45); fd(2) # a regular octogon
+
+
+Animation control
+-----------------
+
+.. function:: delay(delay=None)
+
+ :param delay: positive integer
+
+ Set or return the drawing *delay* in milliseconds. (This is approximately
+ the time interval between two consecutived canvas updates.) The longer the
+ drawing delay, the slower the animation.
+
+ Optional argument:
+
+ >>> screen.delay(15)
+ >>> screen.delay()
+ 15
+
+
+.. function:: tracer(n=None, delay=None)
+
+ :param n: nonnegative integer
+ :param delay: nonnegative integer
+
+ Turn turtle animation on/off and set delay for update drawings. If *n* is
+ given, only each n-th regular screen update is really performed. (Can be
+ used to accelerate the drawing of complex graphics.) Second argument sets
+ delay value (see :func:`delay`).
+
+ >>> screen.tracer(8, 25)
+ >>> dist = 2
+ >>> for i in range(200):
+ ... fd(dist)
+ ... rt(90)
+ ... dist += 2
+
+
+.. function:: update()
+
+ Perform a TurtleScreen update. To be used when tracer is turned off.
+
+See also the RawTurtle/Turtle method :func:`speed`.
+
+
+Using screen events
+-------------------
+
+.. function:: 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 :func:`listen` to the onclick method.
+
+
+.. function:: onkey(fun, key)
+
+ :param fun: a function with no arguments or ``None``
+ :param key: a string: key (e.g. "a") or key-symbol (e.g. "space")
+
+ Bind *fun* to key-release event of key. If *fun* is ``None``, event bindings
+ are removed. Remark: in order to be able to register key-events, TurtleScreen
+ must have the focus. (See method :func:`listen`.)
+
+ >>> def f():
+ ... fd(50)
+ ... lt(60)
+ ...
+ >>> screen.onkey(f, "Up")
+ >>> screen.listen()
+
+
+.. function:: onclick(fun, btn=1, add=None)
+ onscreenclick(fun, btn=1, add=None)
+
+ :param fun: a function with two arguments which will be called with the
+ coordinates of the clicked point on the canvas
+ :param num: number of the mouse-button, defaults to 1 (left mouse button)
+ :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
+ added, otherwise it will replace a former binding
+
+ Bind *fun* to mouse-click events on this screen. If *fun* is ``None``,
+ existing bindings are removed.
+
+ Example for a TurtleScreen instance named ``screen`` and a Turtle instance
+ named turtle:
+
+ >>> screen.onclick(turtle.goto)
+ # Subsequently clicking into the TurtleScreen will
+ # make the turtle move to the clicked point.
+ >>> screen.onclick(None) # remove event binding again
+
+ .. note::
+ This TurtleScreen method is available as a global function only under the
+ name ``onscreenclick``. The global function ``onclick`` is another one
+ derived from the Turtle method ``onclick``.
+
+
+.. function:: ontimer(fun, t=0)
+
+ :param fun: a function with no arguments
+ :param t: a number >= 0
+
+ Install a timer that calls *fun* after *t* milliseconds.
+
+ >>> running = True
+ >>> def f():
+ if running:
+ fd(50)
+ lt(60)
+ screen.ontimer(f, 250)
+ >>> f() ### makes the turtle marching around
+ >>> running = False
+
+
+Settings and special methods
+----------------------------
+
+.. function:: mode(mode=None)
+
+ :param mode: one of the strings "standard", "logo" or "world"
+
+ Set turtle mode ("standard", "logo" or "world") and perform reset. If mode
+ is not given, current mode is returned.
+
+ Mode "standard" is compatible with old :mod:`turtle`. Mode "logo" is
+ compatible with most Logo turtle graphics. Mode "world" uses user-defined
+ "world coordinates". **Attention**: in this mode angles appear distorted if
+ ``x/y`` unit-ratio doesn't equal 1.
+
+ ============ ========================= ===================
+ Mode Initial turtle heading positive angles
+ ============ ========================= ===================
+ "standard" to the right (east) counterclockwise
+ "logo" upward (north) clockwise
+ ============ ========================= ===================
+
+ >>> mode("logo") # resets turtle heading to north
+ >>> mode()
+ "logo"
+
+
+.. function:: colormode(cmode=None)
+
+ :param cmode: one of the values 1.0 or 255
+
+ Return the colormode or set it to 1.0 or 255. Subsequently *r*, *g*, *b*
+ values of color triples have to be in the range 0..\ *cmode*.
+
+ >>> screen.colormode()
+ 1.0
+ >>> screen.colormode(255)
+ >>> turtle.pencolor(240,160,80)
+
+
+.. function:: getcanvas()
+
+ Return the Canvas of this TurtleScreen. Useful for insiders who know what to
+ do with a Tkinter Canvas.
+
+ >>> cv = screen.getcanvas()
+ >>> cv
+ <turtle.ScrolledCanvas instance at 0x010742D8>
+
+
+.. function:: getshapes()
+
+ Return a list of names of all currently available turtle shapes.
+
+ >>> screen.getshapes()
+ ["arrow", "blank", "circle", ..., "turtle"]
+
+
+.. function:: register_shape(name, shape=None)
+ addshape(name, shape=None)
+
+ There are three different ways to call this function:
+
+ (1) *name* is the name of a gif-file and *shape* is ``None``: Install the
+ corresponding image shape.
+
+ .. note::
+ Image shapes *do not* rotate when turning the turtle, so they do not
+ display the heading of the turtle!
+
+ (2) *name* is an arbitrary string and *shape* is a tuple of pairs of
+ coordinates: Install the corresponding polygon shape.
+
+ (3) *name* is an arbitrary string and shape is a (compound) :class:`Shape`
+ object: Install the corresponding compound shape.
+
+ Add a turtle shape to TurtleScreen's shapelist. Only thusly registered
+ shapes can be used by issuing the command ``shape(shapename)``.
+
+ >>> screen.register_shape("turtle.gif")
+ >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))
+
+
+.. function:: turtles()
+
+ Return the list of turtles on the screen.
+
+ >>> for turtle in screen.turtles()
+ ... turtle.color("red")
.. function:: window_height()
- Return the height of the canvas window.
+ Return the height of the turtle window.
+
+ >>> screen.window_height()
+ 480
-This module also does ``from math import *``, so see the documentation for the
-:mod:`math` module for additional constants and functions useful for turtle
-graphics.
+.. function:: window_width()
+
+ Return the width of the turtle window.
+
+ >>> screen.window_width()
+ 640
-.. function:: demo()
+.. _screenspecific:
- Exercise the module a bit.
+Methods specific to Screen, not inherited from TurtleScreen
+-----------------------------------------------------------
+
+.. function:: bye()
+
+ Shut the turtlegraphics window.
-.. exception:: Error
+.. function:: exitonclick()
- Exception raised on any error caught by this module.
-
-For examples, see the code of the :func:`demo` function.
-
-This module defines the following classes:
+ Bind bye() method to mouse clicks on the Screen.
-.. class:: Pen()
+ If the value "using_IDLE" in the configuration dictionary is ``False``
+ (default value), also enter mainloop. Remark: If IDLE with the ``-n`` switch
+ (no subprocess) is used, this value should be set to ``True`` in
+ :file:`turtle.cfg`. In this case IDLE's own mainloop is active also for the
+ client script.
- Define a pen. All above functions can be called as a methods on the given pen.
- The constructor automatically creates a canvas do be drawn on.
+
+.. function:: setup(width=_CFG["width"], height=_CFG["height"], startx=_CFG["leftright"], starty=_CFG["topbottom"])
+
+ Set the size and position of the main window. Default values of arguments
+ are stored in the configuration dicionary and can be changed via a
+ :file:`turtle.cfg` file.
+
+ :param width: if an integer, a size in pixels, if a float, a fraction of the
+ screen; default is 50% of screen
+ :param height: if an integer, the height in pixels, if a float, a fraction of
+ the screen; default is 75% of screen
+ :param 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
+ :param startx: if positive, starting position in pixels from the top
+ edge of the screen, if negative from the bottom edge, if None,
+ center window vertically
+
+ >>> screen.setup (width=200, height=200, startx=0, starty=0)
+ # sets window to 200x200 pixels, in upper left of screen
+ >>> screen.setup(width=.75, height=0.5, startx=None, starty=None)
+ # sets window to 75% of screen by 50% of screen and centers
+
+
+.. function:: title(titlestring)
+
+ :param titlestring: a string that is shown in the titlebar of the turtle
+ graphics window
+
+ Set title of turtle window to *titlestring*.
+
+ >>> screen.title("Welcome to the turtle zoo!")
+
+
+The public classes of the module :mod:`turtle`
+==============================================
+
+
+.. class:: RawTurtle(canvas)
+ RawPen(canvas)
+
+ :param canvas: a :class:`Tkinter.Canvas`, a :class:`ScrolledCanvas` or a
+ :class:`TurtleScreen`
+
+ Create a turtle. The turtle has all methods described above as "methods of
+ Turtle/RawTurtle".
.. class:: Turtle()
- Define a pen. This is essentially a synonym for ``Pen()``; :class:`Turtle` is an
- empty subclass of :class:`Pen`.
+ Subclass of RawTurtle, has the same interface but draws on a default
+ :class:`Screen` object created automatically when needed for the first time.
-.. class:: RawPen(canvas)
+.. class:: TurtleScreen(cv)
- Define a pen which draws on a canvas *canvas*. This is useful if you want to
- use the module to create graphics in a "real" program.
+ :param cv: a :class:`Tkinter.Canvas`
+
+ Provides screen oriented methods like :func:`setbg` etc. that are described
+ above.
+
+.. class:: Screen()
+
+ Subclass of TurtleScreen, with :ref:`four methods added <screenspecific>`.
+
+
+.. class:: ScrolledCavas(master)
+
+ :param 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.
+
+.. class:: Shape(type_, data)
+
+ :param type\_: one of the strings "polygon", "image", "compound"
+
+ Data structure modeling shapes. The pair ``(type_, data)`` must follow this
+ specification:
-.. _pen-rawpen-objects:
+ =========== ===========
+ *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 compund shape has to be constructed using the
+ :meth:`addcomponent` method)
+ =========== ===========
+
+ .. method:: addcomponent(poly, fill, outline=None)
-Turtle, Pen and RawPen Objects
-------------------------------
+ :param poly: a polygon, i.e. a tuple of pairs of numbers
+ :param fill: a color the *poly* will be filled with
+ :param outline: a color for the poly's outline (if given)
+
+ Example:
-Most of the global functions available in the module are also available as
-methods of the :class:`Turtle`, :class:`Pen` and :class:`RawPen` classes,
-affecting only the state of the given pen.
+ >>> poly = ((0,0),(10,-5),(0,10),(-10,-5))
+ >>> s = Shape("compound")
+ >>> s.addcomponent(poly, "red", "blue")
+ # .. add more components and then use register_shape()
-The only method which is more powerful as a method is :func:`degrees`, which
-takes an optional argument letting you specify the number of units
-corresponding to a full circle:
+ See :ref:`compoundshapes`.
-.. method:: Turtle.degrees([fullcircle])
+.. class:: Vec2D(x, y)
- *fullcircle* is by default 360. This can cause the pen to have any angular units
- whatever: give *fullcircle* ``2*pi`` for radians, or 400 for gradians.
+ A two-dimensional vector class, used as a helper class for implementing
+ turtle graphics. May be useful for turtle graphics programs too. Derived
+ from tuple, so a vector is a tuple!
+
+ Provides (for *a*, *b* vectors, *k* number):
+
+ * ``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
+
+
+Help and configuration
+======================
+
+How to use help
+---------------
+
+The public methods of the Screen and Turtle classes are documented extensively
+via docstrings. So these can be used as online-help via the Python help
+facilities:
+
+- When using IDLE, tooltips show the signatures and first lines of the
+ docstrings of typed in function-/method calls.
+
+- Calling :func:`help` on methods or functions displays the docstrings::
+
+ >>> help(Screen.bgcolor)
+ Help on method bgcolor in module turtle:
+
+ bgcolor(self, *args) unbound turtle.Screen method
+ Set or return backgroundcolor of the TurtleScreen.
+
+ Arguments (if given): a color string or three numbers
+ in the range 0..colormode or a 3-tuple of such numbers.
+
+
+ >>> screen.bgcolor("orange")
+ >>> screen.bgcolor()
+ "orange"
+ >>> screen.bgcolor(0.5,0,0.5)
+ >>> screen.bgcolor()
+ "#800080"
+
+ >>> help(Turtle.penup)
+ Help on method penup in module turtle:
+
+ penup(self) unbound turtle.Turtle method
+ Pull the pen up -- no drawing when moving.
+
+ Aliases: penup | pu | up
+
+ No argument
+
+ >>> turtle.penup()
+
+- The docstrings of the functions which are derived from methods have a modified
+ form::
+
+ >>> help(bgcolor)
+ Help on function bgcolor in module turtle:
+
+ bgcolor(*args)
+ Set or return backgroundcolor of the TurtleScreen.
+
+ Arguments (if given): a color string or three numbers
+ in the range 0..colormode or a 3-tuple of such numbers.
+
+ Example::
+
+ >>> bgcolor("orange")
+ >>> bgcolor()
+ "orange"
+ >>> bgcolor(0.5,0,0.5)
+ >>> bgcolor()
+ "#800080"
+
+ >>> help(penup)
+ Help on function penup in module turtle:
+
+ penup()
+ Pull the pen up -- no drawing when moving.
+
+ Aliases: penup | pu | up
+
+ No argument
+
+ Example:
+ >>> penup()
+
+These modified docstrings are created automatically together with the function
+definitions that are derived from the methods at import time.
+
+
+Translation of docstrings into different languages
+--------------------------------------------------
+
+There is a utility to create a dictionary the keys of which are the method names
+and the values of which are the docstrings of the public methods of the classes
+Screen and Turtle.
+
+.. function:: write_docstringdict(filename="turtle_docstringdict")
+
+ :param 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 :file:`{filename}.py`. It is intended to serve as a template
+ for translation of the docstrings into different languages.
+
+If you (or your students) want to use :mod:`turtle` with online help in your
+native language, you have to translate the docstrings and save the resulting
+file as e.g. :file:`turtle_docstringdict_german.py`.
+
+If you have an appropriate entry in your :file:`turtle.cfg` file this dictionary
+will be read in at import time and will replace the original English docstrings.
+
+At the time of this writing there are docstring dictionaries in German and in
+Italian. (Requests please to glingl@aon.at.)
+
+
+
+How to configure Screen and Turtles
+-----------------------------------
+
+The built-in default configuration mimics the appearance and behaviour of the
+old turtle module in order to retain best possible compatibility with it.
+
+If you want to use a different configuration which better reflects the features
+of this module or which better fits to your needs, e.g. for use in a classroom,
+you can prepare a configuration file ``turtle.cfg`` which will be read at import
+time and modify the configuration according to its settings.
+
+The built in configuration would correspond to the following turtle.cfg::
+
+ 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
+
+Short explanation of selected entries:
+
+- The first four lines correspond to the arguments of the :meth:`Screen.setup`
+ method.
+- Line 5 and 6 correspond to the arguments of the method
+ :meth:`Screen.screensize`.
+- *shape* can be any of the built-in shapes, e.g: arrow, turtle, etc. For more
+ info try ``help(shape)``.
+- If you want to use no fillcolor (i.e. make the turtle transparent), you have
+ to write ``fillcolor = ""`` (but all nonempty strings must not have quotes in
+ the cfg-file).
+- If you want to reflect the turtle its state, you have to use ``resizemode =
+ auto``.
+- If you set e.g. ``language = italian`` the docstringdict
+ :file:`turtle_docstringdict_italian.py` will be loaded at import time (if
+ present on the import path, e.g. in the same directory as :mod:`turtle`.
+- The entries *exampleturtle* and *examplescreen* define the names of these
+ objects as they occur in the docstrings. The transformation of
+ method-docstrings to function-docstrings will delete these names from the
+ docstrings.
+- *using_IDLE*: Set this to ``True`` if you regularly work with IDLE and its -n
+ switch ("no subprocess"). This will prevent :func:`exitonclick` to enter the
+ mainloop.
+
+There can be a :file:`turtle.cfg` file in the directory where :mod:`turtle` is
+stored and an additional one in the current working directory. The latter will
+override the settings of the first one.
+
+The :file:`Demo/turtle` directory contains a :file:`turtle.cfg` file. You can
+study it as an example and see its effects when running the demos (preferably
+not from within the demo-viewer).
+
+
+Demo scripts
+============
+
+There is a set of demo scripts in the turtledemo directory located in the
+:file:`Demo/turtle` directory in the source distribution.
+
+It contains:
+
+- a set of 15 demo scripts demonstrating differet features of the new module
+ :mod:`turtle`
+- a demo viewer :file:`turtleDemo.py` which can be used to view the sourcecode
+ of the scripts and run them at the same time. 14 of the examples can be
+ accessed via the Examples menu; all of them can also be run standalone.
+- The example :file:`turtledemo_two_canvases.py` demonstrates the simultaneous
+ use of two canvases with the turtle module. Therefore it only can be run
+ standalone.
+- There is a :file:`turtle.cfg` file in this directory, which also serves as an
+ example for how to write and use such files.
+
+The demoscripts are:
+
++----------------+------------------------------+-----------------------+
+| Name | Description | Features |
++----------------+------------------------------+-----------------------+
+| bytedesign | complex classical | :func:`tracer`, delay,|
+| | turtlegraphics pattern | :func:`update` |
++----------------+------------------------------+-----------------------+
+| chaos | graphs verhust dynamics, | world coordinates |
+| | proves that you must not | |
+| | trust computers' computations| |
++----------------+------------------------------+-----------------------+
+| clock | analog clock showing time | turtles as clock's |
+| | of your computer | hands, ontimer |
++----------------+------------------------------+-----------------------+
+| colormixer | experiment with r, g, b | :func:`ondrag` |
++----------------+------------------------------+-----------------------+
+| fractalcurves | Hilbert & Koch curves | recursion |
++----------------+------------------------------+-----------------------+
+| lindenmayer | ethnomathematics | L-System |
+| | (indian kolams) | |
++----------------+------------------------------+-----------------------+
+| minimal_hanoi | Towers of Hanoi | Rectangular Turtles |
+| | | as Hanoi discs |
+| | | (shape, shapesize) |
++----------------+------------------------------+-----------------------+
+| paint | super minimalistic | :func:`onclick` |
+| | drawing program | |
++----------------+------------------------------+-----------------------+
+| peace | elementary | turtle: appearance |
+| | | and animation |
++----------------+------------------------------+-----------------------+
+| penrose | aperiodic tiling with | :func:`stamp` |
+| | kites and darts | |
++----------------+------------------------------+-----------------------+
+| planet_and_moon| simulation of | compound shapes, |
+| | gravitational system | :class:`Vec2D` |
++----------------+------------------------------+-----------------------+
+| tree | a (graphical) breadth | :func:`clone` |
+| | first tree (using generators)| |
++----------------+------------------------------+-----------------------+
+| wikipedia | a pattern from the wikipedia | :func:`clone`, |
+| | article on turtle graphics | :func:`undo` |
++----------------+------------------------------+-----------------------+
+| yingyang | another elementary example | :func:`circle` |
++----------------+------------------------------+-----------------------+
+
+Have fun!
+
+
+Changes since Python 2.6
+========================
+
+- The methods :meth:`Turtle.tracer`, :meth:`Turtle.window_width` and
+ :meth:`Turtle.window_height` have been eliminated.
+ Methods with these names and functionality are now available only
+ as methods of :class:`Screen`. The functions derived from these remain
+ available. (In fact already in Python 2.6 these methods were merely
+ duplications of the corresponding
+ :class:`TurtleScreen`/:class:`Screen`-methods.)
+
+- The method :meth:`Turtle.fill` has been eliminated.
+ The behaviour of :meth:`begin_fill` and :meth:`end_fill`
+ have changed slightly: now every filling-process must be completed with an
+ ``end_fill()`` call.
+
+- A method :meth:`Turtle.filling` has been added. It returns a boolean
+ value: ``True`` if a filling process is under way, ``False`` otherwise.
+ This behaviour corresponds to a ``fill()`` call without arguments in
+ Python 2.6