turtle — Turtle graphics for Tk
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 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 Tkinter for the underlying
graphics, it needs a version of python installed with Tk support.
The object-oriented interface uses essentially two+two classes:
The TurtleScreen class defines graphics windows as a playground for
the drawing turtles. Its constructor needs a Tkinter.Canvas or a
ScrolledCanvas as argument. It should be used when turtle is
used as part of some application.
The function Screen() returns a singleton object of a
TurtleScreen subclass. This function should be used when
turtle is used as a standalone tool for doing graphics.
As a singleton object, inheriting from its class is not possible.
All methods of TurtleScreen/Screen also exist as functions, i.e. as part of
the procedure-oriented interface.
RawTurtle (alias: RawPen) defines Turtle objects which draw
on a 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 Turtle (alias: Pen),
which draws on “the” 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 Screen and 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.
Overview over available Turtle and Screen methods
Turtle methods
- Turtle motion
- Move and draw
-
- Tell Turtle’s state
-
- Setting and measurement
-
- Pen control
- Drawing state
-
- Color control
-
- Filling
-
- More drawing control
-
- Turtle state
- Visibility
-
- Appearance
-
- Using events
-
- Special Turtle methods
-
Methods of TurtleScreen/Screen
- Window control
-
- Animation control
-
- Using screen events
-
- Settings and special methods
-
- Methods specific to Screen
-
Methods of RawTurtle/Turtle and corresponding functions
Most of the examples in this section refer to a Turtle instance called
turtle.
Turtle motion
-
turtle.forward(distance)
-
turtle.fd(distance)
| Parameters: |
- distancea 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)
-
turtle.back(distance)
-
turtle.bk(distance)
-
turtle.backward(distance)
-
Move the turtle backward by distance, opposite to the direction the
turtle is headed. Do not change the turtle’s heading.
>>> turtle.position()
(0.00, 0.00)
>>> turtle.backward(30)
>>> turtle.position()
(-30.00, 0.00)
-
turtle.right(angle)
-
turtle.rt(angle)
| Parameters: |
- anglea number (integer or float)
|
|---|
Turn turtle right by angle units. (Units are by default degrees, but
can be set via the degrees() and radians() functions.) Angle
orientation depends on the turtle mode, see mode().
>>> turtle.heading()
22.0
>>> turtle.right(45)
>>> turtle.heading()
337.0
-
turtle.left(angle)
-
turtle.lt(angle)
| Parameters: |
- anglea number (integer or float)
|
|---|
Turn turtle left by angle units. (Units are by default degrees, but
can be set via the degrees() and radians() functions.) Angle
orientation depends on the turtle mode, see mode().
>>> turtle.heading()
22.0
>>> turtle.left(45)
>>> turtle.heading()
67.0
-
turtle.goto(x, y=None)
-
turtle.setpos(x, y=None)
-
turtle.setposition(x, y=None)
| Parameters: |
- xa number or a pair/vector of numbers
- ya number or None
|
|---|
If y is None, x must be a pair of coordinates or a Vec2D
(e.g. as returned by pos()).
Move turtle to an absolute position. If the pen is down, draw line. Do
not change the turtle’s orientation.
>>> 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)
-
turtle.setx(x)
| Parameters: |
- xa 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)
-
turtle.sety(y)
| Parameters: |
- ya 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)
-
turtle.setheading(to_angle)
-
turtle.seth(to_angle)
| Parameters: |
- to_anglea 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
-
turtle.home()
- Move turtle to the origin – coordinates (0,0) – and set its heading to
its start-orientation (which depends on the mode, see mode()).
-
turtle.circle(radius, extent=None, steps=None)
| Parameters: |
- radiusa number
- extenta number (or None)
- stepsan 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
-
turtle.dot(size=None, *color)
| Parameters: |
- sizean integer >= 1 (if given)
- colora 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)
-
turtle.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)
-
turtle.clearstamp(stampid)
| Parameters: |
- stampidan integer, must be return value of previous
stamp() call
|
|---|
Delete stamp with given stampid.
>>> turtle.color("blue")
>>> astamp = turtle.stamp()
>>> turtle.fd(50)
>>> turtle.clearstamp(astamp)
-
turtle.clearstamps(n=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()
-
turtle.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()
-
turtle.speed(speed=None)
| Parameters: |
- speedan 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.
Tell Turtle’s state
-
turtle.position()
-
turtle.pos()
Return the turtle’s current location (x,y) (as a Vec2D vector).
>>> turtle.pos()
(0.00, 240.00)
-
turtle.towards(x, y=None)
| Parameters: |
- xa number or a pair/vector of numbers or a turtle instance
- ya 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
-
turtle.xcor()
Return the turtle’s x coordinate.
>>> reset()
>>> turtle.left(60)
>>> turtle.forward(100)
>>> print turtle.xcor()
50.0
-
turtle.ycor()
Return the turtle’s y coordinate.
>>> reset()
>>> turtle.left(60)
>>> turtle.forward(100)
>>> print turtle.ycor()
86.6025403784
-
turtle.heading()
Return the turtle’s current heading (value depends on the turtle mode, see
mode()).
>>> turtle.left(67)
>>> turtle.heading()
67.0
-
turtle.distance(x, y=None)
| Parameters: |
- xa number or a pair/vector of numbers or a turtle instance
- ya 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
-
turtle.degrees(fullcircle=360.0)
-
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
-
turtle.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
-
turtle.pendown()
-
turtle.pd()
-
turtle.down()
- Pull the pen down – drawing when moving.
-
turtle.penup()
-
turtle.pu()
-
turtle.up()
- Pull the pen up – no drawing when moving.
-
turtle.pensize(width=None)
-
turtle.width(width=None)
-
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
-
turtle.pen(pen=None, **pendict)
| Parameters: |
- pena dictionary with some or all of the below listed keys
- pendictone 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 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}
-
turtle.isdown()
Return True if pen is down, False if it’s up.
>>> turtle.penup()
>>> turtle.isdown()
False
>>> turtle.pendown()
>>> turtle.isdown()
True
Color control
-
turtle.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 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"
-
turtle.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 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)
-
turtle.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 pencolor() and
fillcolor().
- color(colorstring), color((r,g,b)), color(r,g,b)
- Inputs as in 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 colormode().
Filling
-
turtle.fill(flag)
| Parameters: |
- flagTrue/False (or 1/0 respectively)
|
|---|
Call fill(True) before drawing the shape you want to fill, and
fill(False) when done. When used without argument: return fillstate
(True if filling, False else).
>>> turtle.fill(True)
>>> for _ in range(3):
... turtle.forward(100)
... turtle.left(120)
...
>>> turtle.fill(False)
-
turtle.begin_fill()
Call just before drawing a shape to be filled. Equivalent to fill(True).
>>> turtle.color("black", "red")
>>> turtle.begin_fill()
>>> turtle.circle(60)
>>> turtle.end_fill()
-
turtle.end_fill()
- Fill the shape drawn after the last call to begin_fill(). Equivalent
to fill(False).
More drawing control
-
turtle.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
-
turtle.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.
-
turtle.write(arg, move=False, align="left", font=("Arial", 8, "normal"))
| Parameters: |
- argobject to be written to the TurtleScreen
- moveTrue/False
- alignone of the strings “left”, “center” or right”
- fonta 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
-
turtle.showturtle()
-
turtle.st()
Make the turtle visible.
>>> turtle.hideturtle()
>>> turtle.showturtle()
-
turtle.hideturtle()
-
turtle.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.isvisible()
Return True if the Turtle is shown, False if it’s hidden.
>>> turtle.hideturtle()
>>> print turtle.isvisible():
False
Appearance
-
turtle.shape(name=None)
| Parameters: |
- namea 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 register_shape().
>>> turtle.shape()
"arrow"
>>> turtle.shape("turtle")
>>> turtle.shape()
"turtle"
-
turtle.resizemode(rmode=None)
| Parameters: |
- rmodeone 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
shapesize().
- “noresize”: no adaption of the turtle’s appearance takes place.
resizemode(“user”) is called by shapesize() when used with arguments.
>>> turtle.resizemode("noresize")
>>> turtle.resizemode()
"noresize"
-
turtle.shapesize(stretch_wid=None, stretch_len=None, outline=None)
| Parameters: |
- stretch_widpositive number
- stretch_lenpositive number
- outlinepositive 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)
-
turtle.tilt(angle)
-
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)
-
turtle.settiltangle(angle)
-
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)
-
turtle.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
-
turtle.onclick(fun, btn=1, add=None)
| Parameters: |
- funa function with two arguments which will be called with the
coordinates of the clicked point on the canvas
- numnumber of the mouse-button, defaults to 1 (left mouse button)
- addTrue 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
-
turtle.onrelease(fun, btn=1, add=None)
| Parameters: |
- funa function with two arguments which will be called with the
coordinates of the clicked point on the canvas
- numnumber of the mouse-button, defaults to 1 (left mouse button)
- addTrue 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.
-
turtle.ondrag(fun, btn=1, add=None)
| Parameters: |
- funa function with two arguments which will be called with the
coordinates of the clicked point on the canvas
- numnumber of the mouse-button, defaults to 1 (left mouse button)
- addTrue 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
-
turtle.begin_poly()
- Start recording the vertices of a polygon. Current turtle position is first
vertex of polygon.
-
turtle.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.
-
turtle.get_poly()
Return the last recorded polygon.
>>> p = turtle.get_poly()
>>> turtle.register_shape("myFavouriteShape", p)
-
turtle.clone()
Create and return a clone of the turtle with same position, heading and
turtle properties.
>>> mick = Turtle()
>>> joe = mick.clone()
-
turtle.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>]
-
turtle.getscreen()
Return the 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")
-
turtle.setundobuffer(size)
-
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 undo() method/function. If size is
None, the undobuffer is disabled.
>>> turtle.setundobuffer(42)
-
turtle.undobufferentries()
Return number of entries in the undobuffer.
>>> while undobufferentries():
... undo()
-
turtle.tracer(flag=None, delay=None)
A replica of the corresponding TurtleScreen method.
Deprecated since version 2.6.
-
turtle.window_width()
-
turtle.window_height()
Both are replicas of the corresponding TurtleScreen methods.
Deprecated since version 2.6.
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 Shape explicitly as described
below:
Create an empty Shape object of type “compound”.
Add as many components to this object as desired, using the
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")
Now add the Shape to the Screen’s shapelist and use it:
>>> register_shape("myshape", s)
>>> shape("myshape")
Note
The Shape class is used internally by the 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
-
turtle.bgcolor(*args)
| Parameters: |
- argsa 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"
-
turtle.bgpic(picname=None)
| Parameters: |
- picnamea 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"
-
turtle.clear()
-
turtle.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.
-
turtle.reset()
-
turtle.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.
-
turtle.screensize(canvwidth=None, canvheight=None, bg=None)
| Parameters: |
- canvwidthpositive integer, new width of canvas in pixels
- canvheightpositive integer, new height of canvas in pixels
- bgcolorstring 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 ;-)
-
turtle.setworldcoordinates(llx, lly, urx, ury)
| Parameters: |
- llxa number, x-coordinate of lower left corner of canvas
- llya number, y-coordinate of lower left corner of canvas
- urxa number, x-coordinate of upper right corner of canvas
- urya 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 octagon
Animation control
-
turtle.delay(delay=None)
-
Set or return the drawing delay in milliseconds. (This is approximately
the time interval between two consecutive canvas updates.) The longer the
drawing delay, the slower the animation.
Optional argument:
>>> screen.delay(15)
>>> screen.delay()
15
-
turtle.tracer(n=None, delay=None)
| Parameters: |
- nnonnegative integer
- delaynonnegative 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 delay()).
>>> screen.tracer(8, 25)
>>> dist = 2
>>> for i in range(200):
... fd(dist)
... rt(90)
... dist += 2
-
turtle.update()
- Perform a TurtleScreen update. To be used when tracer is turned off.
See also the RawTurtle/Turtle method speed().
Using screen events
-
turtle.listen(xdummy=None, ydummy=None)
- Set focus on TurtleScreen (in order to collect key-events). Dummy arguments
are provided in order to be able to pass listen() to the onclick method.
-
turtle.onkey(fun, key)
| Parameters: |
- funa function with no arguments or None
- keya 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 listen().)
>>> def f():
... fd(50)
... lt(60)
...
>>> screen.onkey(f, "Up")
>>> screen.listen()
-
turtle.onclick(fun, btn=1, add=None)
-
turtle.onscreenclick(fun, btn=1, add=None)
| Parameters: |
- funa function with two arguments which will be called with the
coordinates of the clicked point on the canvas
- numnumber of the mouse-button, defaults to 1 (left mouse button)
- addTrue 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.
-
turtle.ontimer(fun, t=0)
| Parameters: |
- funa function with no arguments
- ta 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
-
turtle.mode(mode=None)
| Parameters: |
- modeone 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 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"
-
turtle.colormode(cmode=None)
| Parameters: |
- cmodeone 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)
-
turtle.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>
-
turtle.getshapes()
Return a list of names of all currently available turtle shapes.
>>> screen.getshapes()
["arrow", "blank", "circle", ..., "turtle"]
-
turtle.register_shape(name, shape=None)
-
turtle.addshape(name, shape=None)
There are three different ways to call this function:
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!
name is an arbitrary string and shape is a tuple of pairs of
coordinates: Install the corresponding polygon shape.
name is an arbitrary string and shape is a (compound) 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)))
-
turtle.turtles()
Return the list of turtles on the screen.
>>> for turtle in screen.turtles()
... turtle.color("red")
-
turtle.window_height()
Return the height of the turtle window.
>>> screen.window_height()
480
-
turtle.window_width()
Return the width of the turtle window.
>>> screen.window_width()
640
Methods specific to Screen, not inherited from TurtleScreen
-
turtle.bye()
- Shut the turtlegraphics window.
-
turtle.exitonclick()
Bind bye() method to mouse clicks on the Screen.
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
turtle.cfg. In this case IDLE’s own mainloop is active also for the
client script.
-
turtle.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
turtle.cfg file.
| Parameters: |
- widthif an integer, a size in pixels, if a float, a fraction of the
screen; default is 50% of screen
- heightif an integer, the height in pixels, if a float, a fraction of
the screen; default is 75% of screen
- startxif positive, starting position in pixels from the left
edge of the screen, if negative from the right edge, if None,
center window horizontally
- startxif 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
-
turtle.title(titlestring)
| Parameters: |
- titlestringa 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 turtle
-
class turtle.RawTurtle(canvas)
-
class turtle.RawPen(canvas)
-
-
class turtle.Turtle
- Subclass of RawTurtle, has the same interface but draws on a default
Screen object created automatically when needed for the first time.
-
class turtle.TurtleScreen(cv)
-
Provides screen oriented methods like setbg() etc. that are described
above.
-
class turtle.Screen
- Subclass of TurtleScreen, with four methods added.
-
class turtle.ScrolledCavas(master)
| Parameters: |
- mastersome 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 turtle.Shape(type_, data)
| Parameters: |
- type_one of the strings “polygon”, “image”, “compound”
|
|---|
Data structure modeling shapes. The pair (type_, data) must follow this
specification:
| 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
addcomponent() method) |
-
addcomponent(poly, fill, outline=None)
| Parameters: |
- polya polygon, i.e. a tuple of pairs of numbers
- filla color the poly will be filled with
- outlinea color for the poly’s outline (if given)
|
|---|
Example:
>>> 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()
See Excursus about the use of compound shapes.
-
class turtle.Vec2D(x, y)
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 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.
-
turtle.write_docstringdict(filename="turtle_docstringdict")
| Parameters: |
- filenamea string, used as filename
|
|---|
Create and write docstring-dictionary to a Python script with the given
filename. This function has to be called explicitly (it is not used by the
turtle graphics classes). The docstring dictionary will be written to the
Python script filename.py. It is intended to serve as a template
for translation of the docstrings into different languages.
If you (or your students) want to use turtle with online help in your
native language, you have to translate the docstrings and save the resulting
file as e.g. turtle_docstringdict_german.py.
If you have an appropriate entry in your 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.)
Demo scripts
There is a set of demo scripts in the turtledemo directory located in the
Demo/turtle directory in the source distribution.
It contains:
- a set of 15 demo scripts demonstrating differet features of the new module
turtle
- a demo viewer 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 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 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
turtlegraphics pattern |
tracer(), delay,
update() |
| chaos |
graphs verhust dynamics,
proves that you must not
trust computers’ computations |
world coordinates |
| clock |
analog clock showing time
of your computer |
turtles as clock’s
hands, ontimer |
| colormixer |
experiment with r, g, b |
ondrag() |
| fractalcurves |
Hilbert & Koch curves |
recursion |
| lindenmayer |
ethnomathematics
(indian kolams) |
L-System |
| minimal_hanoi |
Towers of Hanoi |
Rectangular Turtles
as Hanoi discs
(shape, shapesize) |
| paint |
super minimalistic
drawing program |
onclick() |
| peace |
elementary |
turtle: appearance
and animation |
| penrose |
aperiodic tiling with
kites and darts |
stamp() |
| planet_and_moon |
simulation of
gravitational system |
compound shapes,
Vec2D |
| tree |
a (graphical) breadth
first tree (using generators) |
clone() |
| wikipedia |
a pattern from the wikipedia
article on turtle graphics |
clone(),
undo() |
| yingyang |
another elementary example |
circle() |
Have fun!
|
