1 ========================================
2 :mod:`turtle` --- Turtle graphics for Tk
3 ========================================
6 :synopsis: Turtle graphics for Tk
7 .. sectionauthor:: Gregor Lingl <gregor.lingl@aon.at>
17 Turtle graphics is a popular way for introducing programming to kids. It was
18 part of the original Logo programming language developed by Wally Feurzig and
19 Seymour Papert in 1966.
21 Imagine a robotic turtle starting at (0, 0) in the x-y plane. Give it the
22 command ``turtle.forward(15)``, and it moves (on-screen!) 15 pixels in the
23 direction it is facing, drawing a line as it moves. Give it the command
24 ``turtle.left(25)``, and it rotates in-place 25 degrees clockwise.
26 By combining together these and similar commands, intricate shapes and pictures
29 The :mod:`turtle` module is an extended reimplementation of the same-named
30 module from the Python standard distribution up to version Python 2.5.
32 It tries to keep the merits of the old turtle module and to be (nearly) 100%
33 compatible with it. This means in the first place to enable the learning
34 programmer to use all the commands, classes and methods interactively when using
35 the module from within IDLE run with the ``-n`` switch.
37 The turtle module provides turtle graphics primitives, in both object-oriented
38 and procedure-oriented ways. Because it uses :mod:`Tkinter` for the underlying
39 graphics, it needs a version of python installed with Tk support.
41 The object-oriented interface uses essentially two+two classes:
43 1. The :class:`TurtleScreen` class defines graphics windows as a playground for
44 the drawing turtles. Its constructor needs a :class:`Tkinter.Canvas` or a
45 :class:`ScrolledCanvas` as argument. It should be used when :mod:`turtle` is
46 used as part of some application.
48 The function :func:`Screen` returns a singleton object of a
49 :class:`TurtleScreen` subclass. This function should be used when
50 :mod:`turtle` is used as a standalone tool for doing graphics.
51 As a singleton object, inheriting from its class is not possible.
53 All methods of TurtleScreen/Screen also exist as functions, i.e. as part of
54 the procedure-oriented interface.
56 2. :class:`RawTurtle` (alias: :class:`RawPen`) defines Turtle objects which draw
57 on a :class:`TurtleScreen`. Its constructor needs a Canvas, ScrolledCanvas
58 or TurtleScreen as argument, so the RawTurtle objects know where to draw.
60 Derived from RawTurtle is the subclass :class:`Turtle` (alias: :class:`Pen`),
61 which draws on "the" :class:`Screen` - instance which is automatically
62 created, if not already present.
64 All methods of RawTurtle/Turtle also exist as functions, i.e. part of the
65 procedure-oriented interface.
67 The procedural interface provides functions which are derived from the methods
68 of the classes :class:`Screen` and :class:`Turtle`. They have the same names as
69 the corresponding methods. A screen object is automatically created whenever a
70 function derived from a Screen method is called. An (unnamed) turtle object is
71 automatically created whenever any of the functions derived from a Turtle method
74 To use multiple turtles an a screen one has to use the object-oriented interface.
77 In the following documentation the argument list for functions is given.
78 Methods, of course, have the additional first argument *self* which is
82 Overview over available Turtle and Screen methods
83 =================================================
90 | :func:`forward` | :func:`fd`
91 | :func:`backward` | :func:`bk` | :func:`back`
92 | :func:`right` | :func:`rt`
93 | :func:`left` | :func:`lt`
94 | :func:`goto` | :func:`setpos` | :func:`setposition`
97 | :func:`setheading` | :func:`seth`
103 | :func:`clearstamps`
108 | :func:`position` | :func:`pos`
115 Setting and measurement
121 | :func:`pendown` | :func:`pd` | :func:`down`
122 | :func:`penup` | :func:`pu` | :func:`up`
123 | :func:`pensize` | :func:`width`
144 | :func:`showturtle` | :func:`st`
145 | :func:`hideturtle` | :func:`ht`
151 | :func:`shapesize` | :func:`turtlesize`
152 | :func:`settiltangle`
161 Special Turtle methods
166 | :func:`getturtle` | :func:`getpen`
168 | :func:`setundobuffer`
169 | :func:`undobufferentries`
171 | :func:`window_width`
172 | :func:`window_height`
175 Methods of TurtleScreen/Screen
176 ------------------------------
181 | :func:`clear` | :func:`clearscreen`
182 | :func:`reset` | :func:`resetscreen`
184 | :func:`setworldcoordinates`
194 | :func:`onclick` | :func:`onscreenclick`
197 Settings and special methods
202 | :func:`register_shape` | :func:`addshape`
204 | :func:`window_height`
205 | :func:`window_width`
207 Methods specific to Screen
209 | :func:`exitonclick`
214 Methods of RawTurtle/Turtle and corresponding functions
215 =======================================================
217 Most of the examples in this section refer to a Turtle instance called
223 .. function:: forward(distance)
226 :param distance: a number (integer or float)
228 Move the turtle forward by the specified *distance*, in the direction the
233 >>> turtle.position()
235 >>> turtle.forward(25)
236 >>> turtle.position()
238 >>> turtle.forward(-75)
239 >>> turtle.position()
243 .. function:: back(distance)
247 :param distance: a number
249 Move the turtle backward by *distance*, opposite to the direction the
250 turtle is headed. Do not change the turtle's heading.
255 >>> turtle.goto(0, 0)
259 >>> turtle.position()
261 >>> turtle.backward(30)
262 >>> turtle.position()
266 .. function:: right(angle)
269 :param angle: a number (integer or float)
271 Turn turtle right by *angle* units. (Units are by default degrees, but
272 can be set via the :func:`degrees` and :func:`radians` functions.) Angle
273 orientation depends on the turtle mode, see :func:`mode`.
278 >>> turtle.setheading(22)
289 .. function:: left(angle)
292 :param angle: a number (integer or float)
294 Turn turtle left by *angle* units. (Units are by default degrees, but
295 can be set via the :func:`degrees` and :func:`radians` functions.) Angle
296 orientation depends on the turtle mode, see :func:`mode`.
301 >>> turtle.setheading(22)
312 .. function:: goto(x, y=None)
314 setposition(x, y=None)
316 :param x: a number or a pair/vector of numbers
317 :param y: a number or ``None``
319 If *y* is ``None``, *x* must be a pair of coordinates or a :class:`Vec2D`
320 (e.g. as returned by :func:`pos`).
322 Move turtle to an absolute position. If the pen is down, draw line. Do
323 not change the turtle's orientation.
328 >>> turtle.goto(0, 0)
332 >>> tp = turtle.pos()
335 >>> turtle.setpos(60,30)
338 >>> turtle.setpos((20,80))
341 >>> turtle.setpos(tp)
346 .. function:: setx(x)
348 :param x: a number (integer or float)
350 Set the turtle's first coordinate to *x*, leave second coordinate
356 >>> turtle.goto(0, 240)
360 >>> turtle.position()
363 >>> turtle.position()
367 .. function:: sety(y)
369 :param y: a number (integer or float)
371 Set the turtle's second coordinate to *y*, leave first coordinate unchanged.
376 >>> turtle.goto(0, 40)
380 >>> turtle.position()
383 >>> turtle.position()
387 .. function:: setheading(to_angle)
390 :param to_angle: a number (integer or float)
392 Set the orientation of the turtle to *to_angle*. Here are some common
393 directions in degrees:
395 =================== ====================
396 standard mode logo mode
397 =================== ====================
400 180 - west 180 - south
401 270 - south 270 - west
402 =================== ====================
406 >>> turtle.setheading(90)
413 Move turtle to the origin -- coordinates (0,0) -- and set its heading to
414 its start-orientation (which depends on the mode, see :func:`mode`).
419 >>> turtle.setheading(90)
420 >>> turtle.goto(0, -10)
426 >>> turtle.position()
429 >>> turtle.position()
435 .. function:: circle(radius, extent=None, steps=None)
437 :param radius: a number
438 :param extent: a number (or ``None``)
439 :param steps: an integer (or ``None``)
441 Draw a circle with given *radius*. The center is *radius* units left of
442 the turtle; *extent* -- an angle -- determines which part of the circle
443 is drawn. If *extent* is not given, draw the entire circle. If *extent*
444 is not a full circle, one endpoint of the arc is the current pen
445 position. Draw the arc in counterclockwise direction if *radius* is
446 positive, otherwise in clockwise direction. Finally the direction of the
447 turtle is changed by the amount of *extent*.
449 As the circle is approximated by an inscribed regular polygon, *steps*
450 determines the number of steps to use. If not given, it will be
451 calculated automatically. May be used to draw regular polygons.
456 >>> turtle.position()
460 >>> turtle.circle(50)
461 >>> turtle.position()
465 >>> turtle.circle(120, 180) # draw a semicircle
466 >>> turtle.position()
472 .. function:: dot(size=None, *color)
474 :param size: an integer >= 1 (if given)
475 :param color: a colorstring or a numeric color tuple
477 Draw a circular dot with diameter *size*, using *color*. If *size* is
478 not given, the maximum of pensize+4 and 2*pensize is used.
485 >>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50)
486 >>> turtle.position()
492 .. function:: stamp()
494 Stamp a copy of the turtle shape onto the canvas at the current turtle
495 position. Return a stamp_id for that stamp, which can be used to delete
496 it by calling ``clearstamp(stamp_id)``.
500 >>> turtle.color("blue")
506 .. function:: clearstamp(stampid)
508 :param stampid: an integer, must be return value of previous
511 Delete stamp with given *stampid*.
515 >>> turtle.position()
517 >>> turtle.color("blue")
518 >>> astamp = turtle.stamp()
520 >>> turtle.position()
522 >>> turtle.clearstamp(astamp)
523 >>> turtle.position()
527 .. function:: clearstamps(n=None)
529 :param n: an integer (or ``None``)
531 Delete all or first/last *n* of turtle's stamps. If *n* is None, delete
532 all stamps, if *n* > 0 delete first *n* stamps, else if *n* < 0 delete
537 >>> for i in range(8):
538 ... turtle.stamp(); turtle.fd(30)
547 >>> turtle.clearstamps(2)
548 >>> turtle.clearstamps(-2)
549 >>> turtle.clearstamps()
554 Undo (repeatedly) the last turtle action(s). Number of available
555 undo actions is determined by the size of the undobuffer.
559 >>> for i in range(4):
560 ... turtle.fd(50); turtle.lt(80)
562 >>> for i in range(8):
566 .. function:: speed(speed=None)
568 :param speed: an integer in the range 0..10 or a speedstring (see below)
570 Set the turtle's speed to an integer value in the range 0..10. If no
571 argument is given, return current speed.
573 If input is a number greater than 10 or smaller than 0.5, speed is set
574 to 0. Speedstrings are mapped to speedvalues as follows:
582 Speeds from 1 to 10 enforce increasingly faster animation of line drawing
585 Attention: *speed* = 0 means that *no* animation takes
586 place. forward/back makes turtle jump and likewise left/right make the
587 turtle turn instantly.
593 >>> turtle.speed('normal')
604 .. function:: position()
607 Return the turtle's current location (x,y) (as a :class:`Vec2D` vector).
615 .. function:: towards(x, y=None)
617 :param x: a number or a pair/vector of numbers or a turtle instance
618 :param y: a number if *x* is a number, else ``None``
620 Return the angle between the line from turtle position to position specified
621 by (x,y), the vector or the other turtle. This depends on the turtle's start
622 orientation which depends on the mode - "standard"/"world" or "logo").
626 >>> turtle.goto(10, 10)
627 >>> turtle.towards(0,0)
633 Return the turtle's x coordinate.
639 >>> turtle.forward(100)
642 >>> print turtle.xcor()
648 Return the turtle's y coordinate.
654 >>> turtle.forward(100)
655 >>> print turtle.pos()
657 >>> print turtle.ycor()
661 .. function:: heading()
663 Return the turtle's current heading (value depends on the turtle mode, see
674 .. function:: distance(x, y=None)
676 :param x: a number or a pair/vector of numbers or a turtle instance
677 :param y: a number if *x* is a number, else ``None``
679 Return the distance from the turtle to (x,y), the given vector, or the given
680 other turtle, in turtle step units.
685 >>> turtle.distance(30,40)
687 >>> turtle.distance((30,40))
691 >>> turtle.distance(joe)
695 Settings for measurement
696 ------------------------
698 .. function:: degrees(fullcircle=360.0)
700 :param fullcircle: a number
702 Set angle measurement units, i.e. set number of "degrees" for a full circle.
703 Default value is 360 degrees.
711 >>> turtle.degrees(400.0) # angle measurement in gon
714 >>> turtle.degrees(360)
719 .. function:: radians()
721 Set the angle measurement units to radians. Equivalent to
722 ``degrees(2*math.pi)``.
737 >>> turtle.degrees(360)
746 .. function:: pendown()
750 Pull the pen down -- drawing when moving.
753 .. function:: penup()
757 Pull the pen up -- no drawing when moving.
760 .. function:: pensize(width=None)
763 :param width: a positive number
765 Set the line thickness to *width* or return it. If resizemode is set to
766 "auto" and turtleshape is a polygon, that polygon is drawn with the same line
767 thickness. If no argument is given, the current pensize is returned.
773 >>> turtle.pensize(10) # from here on lines of width 10 are drawn
776 .. function:: pen(pen=None, **pendict)
778 :param pen: a dictionary with some or all of the below listed keys
779 :param pendict: one or more keyword-arguments with the below listed keys as keywords
781 Return or set the pen's attributes in a "pen-dictionary" with the following
784 * "shown": True/False
785 * "pendown": True/False
786 * "pencolor": color-string or color-tuple
787 * "fillcolor": color-string or color-tuple
788 * "pensize": positive number
789 * "speed": number in range 0..10
790 * "resizemode": "auto" or "user" or "noresize"
791 * "stretchfactor": (positive number, positive number)
792 * "outline": positive number
795 This dictionary can be used as argument for a subsequent call to :func:`pen`
796 to restore the former pen-state. Moreover one or more of these attributes
797 can be provided as keyword-arguments. This can be used to set several pen
798 attributes in one statement.
801 :options: +NORMALIZE_WHITESPACE
803 >>> turtle.pen(fillcolor="black", pencolor="red", pensize=10)
804 >>> sorted(turtle.pen().items())
805 [('fillcolor', 'black'), ('outline', 1), ('pencolor', 'red'),
806 ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'),
807 ('shown', True), ('speed', 9), ('stretchfactor', (1, 1)), ('tilt', 0)]
808 >>> penstate=turtle.pen()
809 >>> turtle.color("yellow", "")
811 >>> sorted(turtle.pen().items())
812 [('fillcolor', ''), ('outline', 1), ('pencolor', 'yellow'),
813 ('pendown', False), ('pensize', 10), ('resizemode', 'noresize'),
814 ('shown', True), ('speed', 9), ('stretchfactor', (1, 1)), ('tilt', 0)]
815 >>> turtle.pen(penstate, fillcolor="green")
816 >>> sorted(turtle.pen().items())
817 [('fillcolor', 'green'), ('outline', 1), ('pencolor', 'red'),
818 ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'),
819 ('shown', True), ('speed', 9), ('stretchfactor', (1, 1)), ('tilt', 0)]
822 .. function:: isdown()
824 Return ``True`` if pen is down, ``False`` if it's up.
839 .. function:: pencolor(*args)
841 Return or set the pencolor.
843 Four input formats are allowed:
846 Return the current pencolor as color specification string or
847 as a tuple (see example). May be used as input to another
848 color/pencolor/fillcolor call.
850 ``pencolor(colorstring)``
851 Set pencolor to *colorstring*, which is a Tk color specification string,
852 such as ``"red"``, ``"yellow"``, or ``"#33cc8c"``.
854 ``pencolor((r, g, b))``
855 Set pencolor to the RGB color represented by the tuple of *r*, *g*, and
856 *b*. Each of *r*, *g*, and *b* must be in the range 0..colormode, where
857 colormode is either 1.0 or 255 (see :func:`colormode`).
859 ``pencolor(r, g, b)``
860 Set pencolor to the RGB color represented by *r*, *g*, and *b*. Each of
861 *r*, *g*, and *b* must be in the range 0..colormode.
863 If turtleshape is a polygon, the outline of that polygon is drawn with the
870 >>> turtle.pencolor()
872 >>> turtle.pencolor("brown")
873 >>> turtle.pencolor()
875 >>> tup = (0.2, 0.8, 0.55)
876 >>> turtle.pencolor(tup)
877 >>> turtle.pencolor()
878 (0.20000000000000001, 0.80000000000000004, 0.5490196078431373)
880 >>> turtle.pencolor()
882 >>> turtle.pencolor('#32c18f')
883 >>> turtle.pencolor()
887 .. function:: fillcolor(*args)
889 Return or set the fillcolor.
891 Four input formats are allowed:
894 Return the current fillcolor as color specification string, possibly
895 in tuple format (see example). May be used as input to another
896 color/pencolor/fillcolor call.
898 ``fillcolor(colorstring)``
899 Set fillcolor to *colorstring*, which is a Tk color specification string,
900 such as ``"red"``, ``"yellow"``, or ``"#33cc8c"``.
902 ``fillcolor((r, g, b))``
903 Set fillcolor to the RGB color represented by the tuple of *r*, *g*, and
904 *b*. Each of *r*, *g*, and *b* must be in the range 0..colormode, where
905 colormode is either 1.0 or 255 (see :func:`colormode`).
907 ``fillcolor(r, g, b)``
908 Set fillcolor to the RGB color represented by *r*, *g*, and *b*. Each of
909 *r*, *g*, and *b* must be in the range 0..colormode.
911 If turtleshape is a polygon, the interior of that polygon is drawn
912 with the newly set fillcolor.
916 >>> turtle.fillcolor("violet")
917 >>> turtle.fillcolor()
919 >>> col = turtle.pencolor()
922 >>> turtle.fillcolor(col)
923 >>> turtle.fillcolor()
925 >>> turtle.fillcolor('#ffffff')
926 >>> turtle.fillcolor()
930 .. function:: color(*args)
932 Return or set pencolor and fillcolor.
934 Several input formats are allowed. They use 0 to 3 arguments as
938 Return the current pencolor and the current fillcolor as a pair of color
939 specification strings or tuples as returned by :func:`pencolor` and
942 ``color(colorstring)``, ``color((r,g,b))``, ``color(r,g,b)``
943 Inputs as in :func:`pencolor`, set both, fillcolor and pencolor, to the
946 ``color(colorstring1, colorstring2)``, ``color((r1,g1,b1), (r2,g2,b2))``
947 Equivalent to ``pencolor(colorstring1)`` and ``fillcolor(colorstring2)``
948 and analogously if the other input format is used.
950 If turtleshape is a polygon, outline and interior of that polygon is drawn
951 with the newly set colors.
955 >>> turtle.color("red", "green")
958 >>> color("#285078", "#a0c8f0")
960 ((40, 80, 120), (160, 200, 240))
963 See also: Screen method :func:`colormode`.
974 .. function:: fill(flag)
976 :param flag: True/False (or 1/0 respectively)
978 Call ``fill(True)`` before drawing the shape you want to fill, and
979 ``fill(False)`` when done. When used without argument: return fillstate
980 (``True`` if filling, ``False`` else).
984 >>> turtle.fill(True)
985 >>> for _ in range(3):
986 ... turtle.forward(100)
989 >>> turtle.fill(False)
992 .. function:: begin_fill()
994 Call just before drawing a shape to be filled. Equivalent to ``fill(True)``.
997 .. function:: end_fill()
999 Fill the shape drawn after the last call to :func:`begin_fill`. Equivalent
1004 >>> turtle.color("black", "red")
1005 >>> turtle.begin_fill()
1006 >>> turtle.circle(80)
1007 >>> turtle.end_fill()
1010 More drawing control
1011 ~~~~~~~~~~~~~~~~~~~~
1013 .. function:: reset()
1015 Delete the turtle's drawings from the screen, re-center the turtle and set
1016 variables to the default values.
1020 >>> turtle.goto(0,-22)
1021 >>> turtle.left(100)
1022 >>> turtle.position()
1024 >>> turtle.heading()
1027 >>> turtle.position()
1029 >>> turtle.heading()
1033 .. function:: clear()
1035 Delete the turtle's drawings from the screen. Do not move turtle. State and
1036 position of the turtle as well as drawings of other turtles are not affected.
1039 .. function:: write(arg, move=False, align="left", font=("Arial", 8, "normal"))
1041 :param arg: object to be written to the TurtleScreen
1042 :param move: True/False
1043 :param align: one of the strings "left", "center" or right"
1044 :param font: a triple (fontname, fontsize, fonttype)
1046 Write text - the string representation of *arg* - at the current turtle
1047 position according to *align* ("left", "center" or right") and with the given
1048 font. If *move* is True, the pen is moved to the bottom-right corner of the
1049 text. By default, *move* is False.
1051 >>> turtle.write("Home = ", True, align="center")
1052 >>> turtle.write((0,0), True)
1061 .. function:: hideturtle()
1064 Make the turtle invisible. It's a good idea to do this while you're in the
1065 middle of doing some complex drawing, because hiding the turtle speeds up the
1070 >>> turtle.hideturtle()
1073 .. function:: showturtle()
1076 Make the turtle visible.
1080 >>> turtle.showturtle()
1083 .. function:: isvisible()
1085 Return True if the Turtle is shown, False if it's hidden.
1087 >>> turtle.hideturtle()
1088 >>> turtle.isvisible()
1090 >>> turtle.showturtle()
1091 >>> turtle.isvisible()
1098 .. function:: shape(name=None)
1100 :param name: a string which is a valid shapename
1102 Set turtle shape to shape with given *name* or, if name is not given, return
1103 name of current shape. Shape with *name* must exist in the TurtleScreen's
1104 shape dictionary. Initially there are the following polygon shapes: "arrow",
1105 "turtle", "circle", "square", "triangle", "classic". To learn about how to
1106 deal with shapes see Screen method :func:`register_shape`.
1112 >>> turtle.shape("turtle")
1117 .. function:: resizemode(rmode=None)
1119 :param rmode: one of the strings "auto", "user", "noresize"
1121 Set resizemode to one of the values: "auto", "user", "noresize". If *rmode*
1122 is not given, return current resizemode. Different resizemodes have the
1125 - "auto": adapts the appearance of the turtle corresponding to the value of pensize.
1126 - "user": adapts the appearance of the turtle according to the values of
1127 stretchfactor and outlinewidth (outline), which are set by
1129 - "noresize": no adaption of the turtle's appearance takes place.
1131 resizemode("user") is called by :func:`shapesize` when used with arguments.
1135 >>> turtle.resizemode()
1137 >>> turtle.resizemode("auto")
1138 >>> turtle.resizemode()
1142 .. function:: shapesize(stretch_wid=None, stretch_len=None, outline=None)
1143 turtlesize(stretch_wid=None, stretch_len=None, outline=None)
1145 :param stretch_wid: positive number
1146 :param stretch_len: positive number
1147 :param outline: positive number
1149 Return or set the pen's attributes x/y-stretchfactors and/or outline. Set
1150 resizemode to "user". If and only if resizemode is set to "user", the turtle
1151 will be displayed stretched according to its stretchfactors: *stretch_wid* is
1152 stretchfactor perpendicular to its orientation, *stretch_len* is
1153 stretchfactor in direction of its orientation, *outline* determines the width
1154 of the shapes's outline.
1158 >>> turtle.shapesize()
1160 >>> turtle.resizemode("user")
1161 >>> turtle.shapesize(5, 5, 12)
1162 >>> turtle.shapesize()
1164 >>> turtle.shapesize(outline=8)
1165 >>> turtle.shapesize()
1169 .. function:: tilt(angle)
1171 :param angle: a number
1173 Rotate the turtleshape by *angle* from its current tilt-angle, but do *not*
1174 change the turtle's heading (direction of movement).
1179 >>> turtle.shape("circle")
1180 >>> turtle.shapesize(5,2)
1187 .. function:: settiltangle(angle)
1189 :param angle: a number
1191 Rotate the turtleshape to point in the direction specified by *angle*,
1192 regardless of its current tilt-angle. *Do not* change the turtle's heading
1193 (direction of movement).
1198 >>> turtle.shape("circle")
1199 >>> turtle.shapesize(5,2)
1200 >>> turtle.settiltangle(45)
1202 >>> turtle.settiltangle(-45)
1206 .. function:: tiltangle()
1208 Return the current tilt-angle, i.e. the angle between the orientation of the
1209 turtleshape and the heading of the turtle (its direction of movement).
1214 >>> turtle.shape("circle")
1215 >>> turtle.shapesize(5,2)
1217 >>> turtle.tiltangle()
1224 .. function:: onclick(fun, btn=1, add=None)
1226 :param fun: a function with two arguments which will be called with the
1227 coordinates of the clicked point on the canvas
1228 :param num: number of the mouse-button, defaults to 1 (left mouse button)
1229 :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
1230 added, otherwise it will replace a former binding
1232 Bind *fun* to mouse-click events on this turtle. If *fun* is ``None``,
1233 existing bindings are removed. Example for the anonymous turtle, i.e. the
1241 >>> onclick(turn) # Now clicking into the turtle will turn it.
1242 >>> onclick(None) # event-binding will be removed
1245 .. function:: onrelease(fun, btn=1, add=None)
1247 :param fun: a function with two arguments which will be called with the
1248 coordinates of the clicked point on the canvas
1249 :param num: number of the mouse-button, defaults to 1 (left mouse button)
1250 :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
1251 added, otherwise it will replace a former binding
1253 Bind *fun* to mouse-button-release events on this turtle. If *fun* is
1254 ``None``, existing bindings are removed.
1258 >>> class MyTurtle(Turtle):
1259 ... def glow(self,x,y):
1260 ... self.fillcolor("red")
1261 ... def unglow(self,x,y):
1262 ... self.fillcolor("")
1264 >>> turtle = MyTurtle()
1265 >>> turtle.onclick(turtle.glow) # clicking on turtle turns fillcolor red,
1266 >>> turtle.onrelease(turtle.unglow) # releasing turns it to transparent.
1269 .. function:: ondrag(fun, btn=1, add=None)
1271 :param fun: a function with two arguments which will be called with the
1272 coordinates of the clicked point on the canvas
1273 :param num: number of the mouse-button, defaults to 1 (left mouse button)
1274 :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
1275 added, otherwise it will replace a former binding
1277 Bind *fun* to mouse-move events on this turtle. If *fun* is ``None``,
1278 existing bindings are removed.
1280 Remark: Every sequence of mouse-move-events on a turtle is preceded by a
1281 mouse-click event on that turtle.
1285 >>> turtle.ondrag(turtle.goto)
1287 Subsequently, clicking and dragging the Turtle will move it across
1288 the screen thereby producing handdrawings (if pen is down).
1291 Special Turtle methods
1292 ----------------------
1294 .. function:: begin_poly()
1296 Start recording the vertices of a polygon. Current turtle position is first
1300 .. function:: end_poly()
1302 Stop recording the vertices of a polygon. Current turtle position is last
1303 vertex of polygon. This will be connected with the first vertex.
1306 .. function:: get_poly()
1308 Return the last recorded polygon.
1313 >>> turtle.begin_poly()
1319 >>> turtle.end_poly()
1320 >>> p = turtle.get_poly()
1321 >>> register_shape("myFavouriteShape", p)
1324 .. function:: clone()
1326 Create and return a clone of the turtle with same position, heading and
1332 >>> joe = mick.clone()
1335 .. function:: getturtle()
1338 Return the Turtle object itself. Only reasonable use: as a function to
1339 return the "anonymous turtle":
1343 >>> pet = getturtle()
1346 <turtle.Turtle object at 0x...>
1349 .. function:: getscreen()
1351 Return the :class:`TurtleScreen` object the turtle is drawing on.
1352 TurtleScreen methods can then be called for that object.
1356 >>> ts = turtle.getscreen()
1358 <turtle._Screen object at 0x...>
1359 >>> ts.bgcolor("pink")
1362 .. function:: setundobuffer(size)
1364 :param size: an integer or ``None``
1366 Set or disable undobuffer. If *size* is an integer an empty undobuffer of
1367 given size is installed. *size* gives the maximum number of turtle actions
1368 that can be undone by the :func:`undo` method/function. If *size* is
1369 ``None``, the undobuffer is disabled.
1373 >>> turtle.setundobuffer(42)
1376 .. function:: undobufferentries()
1378 Return number of entries in the undobuffer.
1382 >>> while undobufferentries():
1386 .. function:: tracer(flag=None, delay=None)
1388 A replica of the corresponding TurtleScreen method.
1393 .. function:: window_width()
1396 Both are replicas of the corresponding TurtleScreen methods.
1403 Excursus about the use of compound shapes
1404 -----------------------------------------
1406 To use compound turtle shapes, which consist of several polygons of different
1407 color, you must use the helper class :class:`Shape` explicitly as described
1410 1. Create an empty Shape object of type "compound".
1411 2. Add as many components to this object as desired, using the
1412 :meth:`addcomponent` method.
1418 >>> s = Shape("compound")
1419 >>> poly1 = ((0,0),(10,-5),(0,10),(-10,-5))
1420 >>> s.addcomponent(poly1, "red", "blue")
1421 >>> poly2 = ((0,0),(10,-5),(-10,-5))
1422 >>> s.addcomponent(poly2, "blue", "red")
1424 3. Now add the Shape to the Screen's shapelist and use it:
1428 >>> register_shape("myshape", s)
1429 >>> shape("myshape")
1434 The :class:`Shape` class is used internally by the :func:`register_shape`
1435 method in different ways. The application programmer has to deal with the
1436 Shape class *only* when using compound shapes like shown above!
1439 Methods of TurtleScreen/Screen and corresponding functions
1440 ==========================================================
1442 Most of the examples in this section refer to a TurtleScreen instance called
1448 >>> screen = Screen()
1453 .. function:: bgcolor(*args)
1455 :param args: a color string or three numbers in the range 0..colormode or a
1456 3-tuple of such numbers
1458 Set or return background color of the TurtleScreen.
1462 >>> screen.bgcolor("orange")
1463 >>> screen.bgcolor()
1465 >>> screen.bgcolor("#800080")
1466 >>> screen.bgcolor()
1470 .. function:: bgpic(picname=None)
1472 :param picname: a string, name of a gif-file or ``"nopic"``, or ``None``
1474 Set background image or return name of current backgroundimage. If *picname*
1475 is a filename, set the corresponding image as background. If *picname* is
1476 ``"nopic"``, delete background image, if present. If *picname* is ``None``,
1477 return the filename of the current backgroundimage. ::
1481 >>> screen.bgpic("landscape.gif")
1486 .. function:: clear()
1489 Delete all drawings and all turtles from the TurtleScreen. Reset the now
1490 empty TurtleScreen to its initial state: white background, no background
1491 image, no event bindings and tracing on.
1494 This TurtleScreen method is available as a global function only under the
1495 name ``clearscreen``. The global function ``clear`` is another one
1496 derived from the Turtle method ``clear``.
1499 .. function:: reset()
1502 Reset all Turtles on the Screen to their initial state.
1505 This TurtleScreen method is available as a global function only under the
1506 name ``resetscreen``. The global function ``reset`` is another one
1507 derived from the Turtle method ``reset``.
1510 .. function:: screensize(canvwidth=None, canvheight=None, bg=None)
1512 :param canvwidth: positive integer, new width of canvas in pixels
1513 :param canvheight: positive integer, new height of canvas in pixels
1514 :param bg: colorstring or color-tuple, new background color
1516 If no arguments are given, return current (canvaswidth, canvasheight). Else
1517 resize the canvas the turtles are drawing on. Do not alter the drawing
1518 window. To observe hidden parts of the canvas, use the scrollbars. With this
1519 method, one can make visible those parts of a drawing which were outside the
1522 >>> screen.screensize()
1524 >>> screen.screensize(2000,1500)
1525 >>> screen.screensize()
1528 e.g. to search for an erroneously escaped turtle ;-)
1531 .. function:: setworldcoordinates(llx, lly, urx, ury)
1533 :param llx: a number, x-coordinate of lower left corner of canvas
1534 :param lly: a number, y-coordinate of lower left corner of canvas
1535 :param urx: a number, x-coordinate of upper right corner of canvas
1536 :param ury: a number, y-coordinate of upper right corner of canvas
1538 Set up user-defined coordinate system and switch to mode "world" if
1539 necessary. This performs a ``screen.reset()``. If mode "world" is already
1540 active, all drawings are redrawn according to the new coordinates.
1542 **ATTENTION**: in user-defined coordinate systems angles may appear
1548 >>> screen.setworldcoordinates(-50,-7.5,50,7.5)
1549 >>> for _ in range(72):
1552 >>> for _ in range(8):
1553 ... left(45); fd(2) # a regular octagon
1559 >>> for t in turtles():
1566 .. function:: delay(delay=None)
1568 :param delay: positive integer
1570 Set or return the drawing *delay* in milliseconds. (This is approximately
1571 the time interval between two consecutive canvas updates.) The longer the
1572 drawing delay, the slower the animation.
1585 .. function:: tracer(n=None, delay=None)
1587 :param n: nonnegative integer
1588 :param delay: nonnegative integer
1590 Turn turtle animation on/off and set delay for update drawings. If *n* is
1591 given, only each n-th regular screen update is really performed. (Can be
1592 used to accelerate the drawing of complex graphics.) Second argument sets
1593 delay value (see :func:`delay`).
1597 >>> screen.tracer(8, 25)
1599 >>> for i in range(200):
1605 .. function:: update()
1607 Perform a TurtleScreen update. To be used when tracer is turned off.
1609 See also the RawTurtle/Turtle method :func:`speed`.
1615 .. function:: listen(xdummy=None, ydummy=None)
1617 Set focus on TurtleScreen (in order to collect key-events). Dummy arguments
1618 are provided in order to be able to pass :func:`listen` to the onclick method.
1621 .. function:: onkey(fun, key)
1623 :param fun: a function with no arguments or ``None``
1624 :param key: a string: key (e.g. "a") or key-symbol (e.g. "space")
1626 Bind *fun* to key-release event of key. If *fun* is ``None``, event bindings
1627 are removed. Remark: in order to be able to register key-events, TurtleScreen
1628 must have the focus. (See method :func:`listen`.)
1636 >>> screen.onkey(f, "Up")
1640 .. function:: onclick(fun, btn=1, add=None)
1641 onscreenclick(fun, btn=1, add=None)
1643 :param fun: a function with two arguments which will be called with the
1644 coordinates of the clicked point on the canvas
1645 :param num: number of the mouse-button, defaults to 1 (left mouse button)
1646 :param add: ``True`` or ``False`` -- if ``True``, a new binding will be
1647 added, otherwise it will replace a former binding
1649 Bind *fun* to mouse-click events on this screen. If *fun* is ``None``,
1650 existing bindings are removed.
1652 Example for a TurtleScreen instance named ``screen`` and a Turtle instance
1657 >>> screen.onclick(turtle.goto) # Subsequently clicking into the TurtleScreen will
1658 >>> # make the turtle move to the clicked point.
1659 >>> screen.onclick(None) # remove event binding again
1662 This TurtleScreen method is available as a global function only under the
1663 name ``onscreenclick``. The global function ``onclick`` is another one
1664 derived from the Turtle method ``onclick``.
1667 .. function:: ontimer(fun, t=0)
1669 :param fun: a function with no arguments
1670 :param t: a number >= 0
1672 Install a timer that calls *fun* after *t* milliseconds.
1681 ... screen.ontimer(f, 250)
1682 >>> f() ### makes the turtle march around
1686 Settings and special methods
1687 ----------------------------
1689 .. function:: mode(mode=None)
1691 :param mode: one of the strings "standard", "logo" or "world"
1693 Set turtle mode ("standard", "logo" or "world") and perform reset. If mode
1694 is not given, current mode is returned.
1696 Mode "standard" is compatible with old :mod:`turtle`. Mode "logo" is
1697 compatible with most Logo turtle graphics. Mode "world" uses user-defined
1698 "world coordinates". **Attention**: in this mode angles appear distorted if
1699 ``x/y`` unit-ratio doesn't equal 1.
1701 ============ ========================= ===================
1702 Mode Initial turtle heading positive angles
1703 ============ ========================= ===================
1704 "standard" to the right (east) counterclockwise
1705 "logo" upward (north) clockwise
1706 ============ ========================= ===================
1710 >>> mode("logo") # resets turtle heading to north
1715 .. function:: colormode(cmode=None)
1717 :param cmode: one of the values 1.0 or 255
1719 Return the colormode or set it to 1.0 or 255. Subsequently *r*, *g*, *b*
1720 values of color triples have to be in the range 0..\ *cmode*.
1724 >>> screen.colormode(1)
1725 >>> turtle.pencolor(240, 160, 80)
1726 Traceback (most recent call last):
1728 TurtleGraphicsError: bad color sequence: (240, 160, 80)
1729 >>> screen.colormode()
1731 >>> screen.colormode(255)
1732 >>> screen.colormode()
1734 >>> turtle.pencolor(240,160,80)
1737 .. function:: getcanvas()
1739 Return the Canvas of this TurtleScreen. Useful for insiders who know what to
1740 do with a Tkinter Canvas.
1744 >>> cv = screen.getcanvas()
1746 <turtle.ScrolledCanvas instance at 0x...>
1749 .. function:: getshapes()
1751 Return a list of names of all currently available turtle shapes.
1755 >>> screen.getshapes()
1756 ['arrow', 'blank', 'circle', ..., 'turtle']
1759 .. function:: register_shape(name, shape=None)
1760 addshape(name, shape=None)
1762 There are three different ways to call this function:
1764 (1) *name* is the name of a gif-file and *shape* is ``None``: Install the
1765 corresponding image shape. ::
1767 >>> screen.register_shape("turtle.gif")
1770 Image shapes *do not* rotate when turning the turtle, so they do not
1771 display the heading of the turtle!
1773 (2) *name* is an arbitrary string and *shape* is a tuple of pairs of
1774 coordinates: Install the corresponding polygon shape.
1778 >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))
1780 (3) *name* is an arbitrary string and shape is a (compound) :class:`Shape`
1781 object: Install the corresponding compound shape.
1783 Add a turtle shape to TurtleScreen's shapelist. Only thusly registered
1784 shapes can be used by issuing the command ``shape(shapename)``.
1787 .. function:: turtles()
1789 Return the list of turtles on the screen.
1793 >>> for turtle in screen.turtles():
1794 ... turtle.color("red")
1797 .. function:: window_height()
1799 Return the height of the turtle window. ::
1801 >>> screen.window_height()
1805 .. function:: window_width()
1807 Return the width of the turtle window. ::
1809 >>> screen.window_width()
1815 Methods specific to Screen, not inherited from TurtleScreen
1816 -----------------------------------------------------------
1820 Shut the turtlegraphics window.
1823 .. function:: exitonclick()
1825 Bind bye() method to mouse clicks on the Screen.
1828 If the value "using_IDLE" in the configuration dictionary is ``False``
1829 (default value), also enter mainloop. Remark: If IDLE with the ``-n`` switch
1830 (no subprocess) is used, this value should be set to ``True`` in
1831 :file:`turtle.cfg`. In this case IDLE's own mainloop is active also for the
1835 .. function:: setup(width=_CFG["width"], height=_CFG["height"], startx=_CFG["leftright"], starty=_CFG["topbottom"])
1837 Set the size and position of the main window. Default values of arguments
1838 are stored in the configuration dicionary and can be changed via a
1839 :file:`turtle.cfg` file.
1841 :param width: if an integer, a size in pixels, if a float, a fraction of the
1842 screen; default is 50% of screen
1843 :param height: if an integer, the height in pixels, if a float, a fraction of
1844 the screen; default is 75% of screen
1845 :param startx: if positive, starting position in pixels from the left
1846 edge of the screen, if negative from the right edge, if None,
1847 center window horizontally
1848 :param startx: if positive, starting position in pixels from the top
1849 edge of the screen, if negative from the bottom edge, if None,
1850 center window vertically
1854 >>> screen.setup (width=200, height=200, startx=0, starty=0)
1855 >>> # sets window to 200x200 pixels, in upper left of screen
1856 >>> screen.setup(width=.75, height=0.5, startx=None, starty=None)
1857 >>> # sets window to 75% of screen by 50% of screen and centers
1860 .. function:: title(titlestring)
1862 :param titlestring: a string that is shown in the titlebar of the turtle
1865 Set title of turtle window to *titlestring*.
1869 >>> screen.title("Welcome to the turtle zoo!")
1872 The public classes of the module :mod:`turtle`
1873 ==============================================
1876 .. class:: RawTurtle(canvas)
1879 :param canvas: a :class:`Tkinter.Canvas`, a :class:`ScrolledCanvas` or a
1880 :class:`TurtleScreen`
1882 Create a turtle. The turtle has all methods described above as "methods of
1888 Subclass of RawTurtle, has the same interface but draws on a default
1889 :class:`Screen` object created automatically when needed for the first time.
1892 .. class:: TurtleScreen(cv)
1894 :param cv: a :class:`Tkinter.Canvas`
1896 Provides screen oriented methods like :func:`setbg` etc. that are described
1901 Subclass of TurtleScreen, with :ref:`four methods added <screenspecific>`.
1904 .. class:: ScrolledCavas(master)
1906 :param master: some Tkinter widget to contain the ScrolledCanvas, i.e.
1907 a Tkinter-canvas with scrollbars added
1909 Used by class Screen, which thus automatically provides a ScrolledCanvas as
1910 playground for the turtles.
1912 .. class:: Shape(type_, data)
1914 :param type\_: one of the strings "polygon", "image", "compound"
1916 Data structure modeling shapes. The pair ``(type_, data)`` must follow this
1920 =========== ===========
1922 =========== ===========
1923 "polygon" a polygon-tuple, i.e. a tuple of pairs of coordinates
1924 "image" an image (in this form only used internally!)
1925 "compound" ``None`` (a compound shape has to be constructed using the
1926 :meth:`addcomponent` method)
1927 =========== ===========
1929 .. method:: addcomponent(poly, fill, outline=None)
1931 :param poly: a polygon, i.e. a tuple of pairs of numbers
1932 :param fill: a color the *poly* will be filled with
1933 :param outline: a color for the poly's outline (if given)
1939 >>> poly = ((0,0),(10,-5),(0,10),(-10,-5))
1940 >>> s = Shape("compound")
1941 >>> s.addcomponent(poly, "red", "blue")
1942 >>> # ... add more components and then use register_shape()
1944 See :ref:`compoundshapes`.
1947 .. class:: Vec2D(x, y)
1949 A two-dimensional vector class, used as a helper class for implementing
1950 turtle graphics. May be useful for turtle graphics programs too. Derived
1951 from tuple, so a vector is a tuple!
1953 Provides (for *a*, *b* vectors, *k* number):
1955 * ``a + b`` vector addition
1956 * ``a - b`` vector subtraction
1957 * ``a * b`` inner product
1958 * ``k * a`` and ``a * k`` multiplication with scalar
1959 * ``abs(a)`` absolute value of a
1960 * ``a.rotate(angle)`` rotation
1963 Help and configuration
1964 ======================
1969 The public methods of the Screen and Turtle classes are documented extensively
1970 via docstrings. So these can be used as online-help via the Python help
1973 - When using IDLE, tooltips show the signatures and first lines of the
1974 docstrings of typed in function-/method calls.
1976 - Calling :func:`help` on methods or functions displays the docstrings::
1978 >>> help(Screen.bgcolor)
1979 Help on method bgcolor in module turtle:
1981 bgcolor(self, *args) unbound turtle.Screen method
1982 Set or return backgroundcolor of the TurtleScreen.
1984 Arguments (if given): a color string or three numbers
1985 in the range 0..colormode or a 3-tuple of such numbers.
1988 >>> screen.bgcolor("orange")
1989 >>> screen.bgcolor()
1991 >>> screen.bgcolor(0.5,0,0.5)
1992 >>> screen.bgcolor()
1995 >>> help(Turtle.penup)
1996 Help on method penup in module turtle:
1998 penup(self) unbound turtle.Turtle method
1999 Pull the pen up -- no drawing when moving.
2001 Aliases: penup | pu | up
2007 - The docstrings of the functions which are derived from methods have a modified
2011 Help on function bgcolor in module turtle:
2014 Set or return backgroundcolor of the TurtleScreen.
2016 Arguments (if given): a color string or three numbers
2017 in the range 0..colormode or a 3-tuple of such numbers.
2021 >>> bgcolor("orange")
2024 >>> bgcolor(0.5,0,0.5)
2029 Help on function penup in module turtle:
2032 Pull the pen up -- no drawing when moving.
2034 Aliases: penup | pu | up
2041 These modified docstrings are created automatically together with the function
2042 definitions that are derived from the methods at import time.
2045 Translation of docstrings into different languages
2046 --------------------------------------------------
2048 There is a utility to create a dictionary the keys of which are the method names
2049 and the values of which are the docstrings of the public methods of the classes
2052 .. function:: write_docstringdict(filename="turtle_docstringdict")
2054 :param filename: a string, used as filename
2056 Create and write docstring-dictionary to a Python script with the given
2057 filename. This function has to be called explicitly (it is not used by the
2058 turtle graphics classes). The docstring dictionary will be written to the
2059 Python script :file:`{filename}.py`. It is intended to serve as a template
2060 for translation of the docstrings into different languages.
2062 If you (or your students) want to use :mod:`turtle` with online help in your
2063 native language, you have to translate the docstrings and save the resulting
2064 file as e.g. :file:`turtle_docstringdict_german.py`.
2066 If you have an appropriate entry in your :file:`turtle.cfg` file this dictionary
2067 will be read in at import time and will replace the original English docstrings.
2069 At the time of this writing there are docstring dictionaries in German and in
2070 Italian. (Requests please to glingl@aon.at.)
2074 How to configure Screen and Turtles
2075 -----------------------------------
2077 The built-in default configuration mimics the appearance and behaviour of the
2078 old turtle module in order to retain best possible compatibility with it.
2080 If you want to use a different configuration which better reflects the features
2081 of this module or which better fits to your needs, e.g. for use in a classroom,
2082 you can prepare a configuration file ``turtle.cfg`` which will be read at import
2083 time and modify the configuration according to its settings.
2085 The built in configuration would correspond to the following turtle.cfg::
2096 undobuffersize = 1000
2100 resizemode = noresize
2103 exampleturtle = turtle
2104 examplescreen = screen
2105 title = Python Turtle Graphics
2108 Short explanation of selected entries:
2110 - The first four lines correspond to the arguments of the :meth:`Screen.setup`
2112 - Line 5 and 6 correspond to the arguments of the method
2113 :meth:`Screen.screensize`.
2114 - *shape* can be any of the built-in shapes, e.g: arrow, turtle, etc. For more
2115 info try ``help(shape)``.
2116 - If you want to use no fillcolor (i.e. make the turtle transparent), you have
2117 to write ``fillcolor = ""`` (but all nonempty strings must not have quotes in
2119 - If you want to reflect the turtle its state, you have to use ``resizemode =
2121 - If you set e.g. ``language = italian`` the docstringdict
2122 :file:`turtle_docstringdict_italian.py` will be loaded at import time (if
2123 present on the import path, e.g. in the same directory as :mod:`turtle`.
2124 - The entries *exampleturtle* and *examplescreen* define the names of these
2125 objects as they occur in the docstrings. The transformation of
2126 method-docstrings to function-docstrings will delete these names from the
2128 - *using_IDLE*: Set this to ``True`` if you regularly work with IDLE and its -n
2129 switch ("no subprocess"). This will prevent :func:`exitonclick` to enter the
2132 There can be a :file:`turtle.cfg` file in the directory where :mod:`turtle` is
2133 stored and an additional one in the current working directory. The latter will
2134 override the settings of the first one.
2136 The :file:`Demo/turtle` directory contains a :file:`turtle.cfg` file. You can
2137 study it as an example and see its effects when running the demos (preferably
2138 not from within the demo-viewer).
2144 There is a set of demo scripts in the turtledemo directory located in the
2145 :file:`Demo/turtle` directory in the source distribution.
2149 - a set of 15 demo scripts demonstrating different features of the new module
2151 - a demo viewer :file:`turtleDemo.py` which can be used to view the sourcecode
2152 of the scripts and run them at the same time. 14 of the examples can be
2153 accessed via the Examples menu; all of them can also be run standalone.
2154 - The example :file:`turtledemo_two_canvases.py` demonstrates the simultaneous
2155 use of two canvases with the turtle module. Therefore it only can be run
2157 - There is a :file:`turtle.cfg` file in this directory, which also serves as an
2158 example for how to write and use such files.
2160 The demoscripts are:
2162 +----------------+------------------------------+-----------------------+
2163 | Name | Description | Features |
2164 +----------------+------------------------------+-----------------------+
2165 | bytedesign | complex classical | :func:`tracer`, delay,|
2166 | | turtlegraphics pattern | :func:`update` |
2167 +----------------+------------------------------+-----------------------+
2168 | chaos | graphs verhust dynamics, | world coordinates |
2169 | | proves that you must not | |
2170 | | trust computers' computations| |
2171 +----------------+------------------------------+-----------------------+
2172 | clock | analog clock showing time | turtles as clock's |
2173 | | of your computer | hands, ontimer |
2174 +----------------+------------------------------+-----------------------+
2175 | colormixer | experiment with r, g, b | :func:`ondrag` |
2176 +----------------+------------------------------+-----------------------+
2177 | fractalcurves | Hilbert & Koch curves | recursion |
2178 +----------------+------------------------------+-----------------------+
2179 | lindenmayer | ethnomathematics | L-System |
2180 | | (indian kolams) | |
2181 +----------------+------------------------------+-----------------------+
2182 | minimal_hanoi | Towers of Hanoi | Rectangular Turtles |
2183 | | | as Hanoi discs |
2184 | | | (shape, shapesize) |
2185 +----------------+------------------------------+-----------------------+
2186 | paint | super minimalistic | :func:`onclick` |
2187 | | drawing program | |
2188 +----------------+------------------------------+-----------------------+
2189 | peace | elementary | turtle: appearance |
2190 | | | and animation |
2191 +----------------+------------------------------+-----------------------+
2192 | penrose | aperiodic tiling with | :func:`stamp` |
2193 | | kites and darts | |
2194 +----------------+------------------------------+-----------------------+
2195 | planet_and_moon| simulation of | compound shapes, |
2196 | | gravitational system | :class:`Vec2D` |
2197 +----------------+------------------------------+-----------------------+
2198 | tree | a (graphical) breadth | :func:`clone` |
2199 | | first tree (using generators)| |
2200 +----------------+------------------------------+-----------------------+
2201 | wikipedia | a pattern from the wikipedia | :func:`clone`, |
2202 | | article on turtle graphics | :func:`undo` |
2203 +----------------+------------------------------+-----------------------+
2204 | yingyang | another elementary example | :func:`circle` |
2205 +----------------+------------------------------+-----------------------+
2212 >>> for turtle in turtles():
2215 >>> turtle.goto(-200,25)
2216 >>> turtle.pendown()
2217 >>> turtle.write("No one expects the Spanish Inquisition!",
2218 ... font=("Arial", 20, "normal"))
2220 >>> turtle.goto(-100,-50)
2221 >>> turtle.pendown()
2222 >>> turtle.write("Our two chief Turtles are...",
2223 ... font=("Arial", 16, "normal"))
2225 >>> turtle.goto(-450,-75)
2226 >>> turtle.write(str(turtles()))