turtle — Turtle graphics Source code: Lib/turtle.py Introduction Turtle graphics is a popular way for introducing programming to kids. It was part of the original Logo programming language developed by Wally Feurzeig, Seymour Papert and Cynthia Solomon in 1967. Imagine a robotic turtle starting at (0, 0) in the x-y plane. After an import turtle, 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.right(25), and it rotates in-place 25 degrees clockwise.  Turtle star Turtle can draw intricate shapes using programs that repeat simple moves.  from turtle import *
color('red', 'yellow')
begin_fill()
while True:
    forward(200)
    left(170)
    if abs(pos()) < 1:
        break
end_fill()
done()
  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 automatically 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 on 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 of 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
Input 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
distance – a number (integer or float)   Move the turtle forward by the specified distance, in the direction the turtle is headed. >>> turtle.position()
(0.00,0.00)
>>> turtle.forward(25)
>>> turtle.position()
(25.00,0.00)
>>> turtle.forward(-75)
>>> turtle.position()
(-50.00,0.00)

turtle.back(distance)
turtle.bk(distance)
turtle.backward(distance)
 Parameters
distance – a number   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
angle – a 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
angle – a 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

x – a number or a pair/vector of numbers
y – a 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
x – a number (integer or float)   Set the turtle’s first coordinate to x, leave second coordinate unchanged. >>> turtle.position()
(0.00,240.00)
>>> turtle.setx(10)
>>> turtle.position()
(10.00,240.00)

turtle.sety(y)
 Parameters
y – a number (integer or float)   Set the turtle’s second coordinate to y, leave first 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_angle – a number (integer or float)   Set the orientation of the turtle to to_angle. Here are some common directions in degrees:
standard mode logo mode
0 - east 0 - north
90 - north 90 - east
180 - west 180 - south
270 - south 270 - west   >>> turtle.setheading(90)
>>> turtle.heading()
90.0

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.heading()
90.0
>>> turtle.position()
(0.00,-10.00)
>>> turtle.home()
>>> turtle.position()
(0.00,0.00)
>>> turtle.heading()
0.0

turtle.circle(radius, extent=None, steps=None)
 Parameters

radius – a number
extent – a number (or None)
steps – an integer (or None)    Draw a circle with given radius. The center is radius units left of the turtle; extent – an angle – determines which part of the circle is drawn. If extent is not given, draw the entire circle. If extent is not a full circle, one endpoint of the arc is the current pen position. Draw the arc in counterclockwise direction if radius is positive, otherwise in clockwise direction. Finally the direction of the turtle is changed by the amount of extent. As the circle is approximated by an inscribed regular polygon, steps determines the number of steps to use. If not given, it will be calculated automatically. May be used to draw regular polygons. >>> turtle.home()
>>> turtle.position()
(0.00,0.00)
>>> turtle.heading()
0.0
>>> turtle.circle(50)
>>> turtle.position()
(-0.00,0.00)
>>> turtle.heading()
0.0
>>> turtle.circle(120, 180)  # draw a semicircle
>>> turtle.position()
(0.00,240.00)
>>> turtle.heading()
180.0

turtle.dot(size=None, *color)
 Parameters

size – an integer >= 1 (if given)
color – a colorstring or a numeric color tuple    Draw a circular dot with diameter size, using color. If size is not given, the maximum of pensize+4 and 2*pensize is used. >>> turtle.home()
>>> turtle.dot()
>>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50)
>>> turtle.position()
(100.00,-0.00)
>>> turtle.heading()
0.0

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()
11
>>> turtle.fd(50)

turtle.clearstamp(stampid)
 Parameters
stampid – an integer, must be return value of previous stamp() call   Delete stamp with given stampid. >>> turtle.position()
(150.00,-0.00)
>>> turtle.color("blue")
>>> astamp = turtle.stamp()
>>> turtle.fd(50)
>>> turtle.position()
(200.00,-0.00)
>>> turtle.clearstamp(astamp)
>>> turtle.position()
(200.00,-0.00)

turtle.clearstamps(n=None)
 Parameters
n – an integer (or None)   Delete all or first/last n of turtle’s stamps. If n is None, delete all stamps, if n > 0 delete first n stamps, else if n < 0 delete last n stamps. >>> for i in range(8):
...     turtle.stamp(); turtle.fd(30)
13
14
15
16
17
18
19
20
>>> 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
speed – an integer in the range 0..10 or a speedstring (see below)   Set the turtle’s speed to an integer value in the range 0..10. If no argument is given, return current speed. If input is a number greater than 10 or smaller than 0.5, speed is set to 0. Speedstrings are mapped to speedvalues as follows:  “fastest”: 0 “fast”: 10 “normal”: 6 “slow”: 3 “slowest”: 1  Speeds from 1 to 10 enforce increasingly faster animation of line drawing and turtle turning. Attention: speed = 0 means that no animation takes place. forward/back makes turtle jump and likewise left/right make the turtle turn instantly. >>> turtle.speed()
3
>>> turtle.speed('normal')
>>> turtle.speed()
6
>>> turtle.speed(9)
>>> turtle.speed()
9

 Tell Turtle’s state
turtle.position()
turtle.pos()
Return the turtle’s current location (x,y) (as a Vec2D vector). >>> turtle.pos()
(440.00,-0.00)

turtle.towards(x, y=None)
 Parameters

x – a number or a pair/vector of numbers or a turtle instance
y – a number if x is a number, else None
    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.goto(10, 10)
>>> turtle.towards(0,0)
225.0

turtle.xcor()
Return the turtle’s x coordinate. >>> turtle.home()
>>> turtle.left(50)
>>> turtle.forward(100)
>>> turtle.pos()
(64.28,76.60)
>>> print(round(turtle.xcor(), 5))
64.27876

turtle.ycor()
Return the turtle’s y coordinate. >>> turtle.home()
>>> turtle.left(60)
>>> turtle.forward(100)
>>> print(turtle.pos())
(50.00,86.60)
>>> print(round(turtle.ycor(), 5))
86.60254

turtle.heading()
Return the turtle’s current heading (value depends on the turtle mode, see mode()). >>> turtle.home()
>>> turtle.left(67)
>>> turtle.heading()
67.0

turtle.distance(x, y=None)
 Parameters

x – a number or a pair/vector of numbers or a turtle instance
y – a number if x is a number, else None
    Return the distance from the turtle to (x,y), the given vector, or the given other turtle, in turtle step units. >>> turtle.home()
>>> turtle.distance(30,40)
50.0
>>> turtle.distance((30,40))
50.0
>>> joe = Turtle()
>>> joe.forward(77)
>>> turtle.distance(joe)
77.0

 Settings for measurement
turtle.degrees(fullcircle=360.0)
 Parameters
fullcircle – a number   Set angle measurement units, i.e. set number of “degrees” for a full circle. Default value is 360 degrees. >>> turtle.home()
>>> turtle.left(90)
>>> turtle.heading()
90.0

Change angle measurement unit to grad (also known as gon,
grade, or gradian and equals 1/100-th of the right angle.)
>>> turtle.degrees(400.0)
>>> turtle.heading()
100.0
>>> turtle.degrees(360)
>>> turtle.heading()
90.0

turtle.radians()
Set the angle measurement units to radians. Equivalent to degrees(2*math.pi). >>> turtle.home()
>>> turtle.left(90)
>>> turtle.heading()
90.0
>>> 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)
 Parameters
width – a positive number   Set the line thickness to width or return it. If resizemode is set to “auto” and turtleshape is a polygon, that polygon is drawn with the same line thickness. If no argument is given, the current pensize is returned. >>> turtle.pensize()
1
>>> turtle.pensize(10)   # from here on lines of width 10 are drawn

turtle.pen(pen=None, **pendict)
 Parameters

pen – a dictionary with some or all of the below listed keys
pendict – one or more keyword-arguments with the below listed keys as keywords    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 dictionary 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)
>>> sorted(turtle.pen().items())
[('fillcolor', 'black'), ('outline', 1), ('pencolor', 'red'),
 ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'),
 ('shearfactor', 0.0), ('shown', True), ('speed', 9),
 ('stretchfactor', (1.0, 1.0)), ('tilt', 0.0)]
>>> penstate=turtle.pen()
>>> turtle.color("yellow", "")
>>> turtle.penup()
>>> sorted(turtle.pen().items())[:3]
[('fillcolor', ''), ('outline', 1), ('pencolor', 'yellow')]
>>> turtle.pen(penstate, fillcolor="green")
>>> sorted(turtle.pen().items())[:3]
[('fillcolor', 'green'), ('outline', 1), ('pencolor', 'red')]

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 or as a tuple (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.  >>> colormode()
 1.0
 >>> turtle.pencolor()
 'red'
 >>> turtle.pencolor("brown")
 >>> turtle.pencolor()
 'brown'
 >>> tup = (0.2, 0.8, 0.55)
 >>> turtle.pencolor(tup)
 >>> turtle.pencolor()
 (0.2, 0.8, 0.5490196078431373)
 >>> colormode(255)
 >>> turtle.pencolor()
 (51.0, 204.0, 140.0)
 >>> turtle.pencolor('#32c18f')
 >>> turtle.pencolor()
 (50.0, 193.0, 143.0)

turtle.fillcolor(*args)
Return or set the fillcolor. Four input formats are allowed:
fillcolor()

Return the current fillcolor as color specification string, possibly in tuple 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")
 >>> turtle.fillcolor()
 'violet'
 >>> turtle.pencolor()
 (50.0, 193.0, 143.0)
 >>> turtle.fillcolor((50, 193, 143))  # Integers, not floats
 >>> turtle.fillcolor()
 (50.0, 193.0, 143.0)
 >>> turtle.fillcolor('#ffffff')
 >>> turtle.fillcolor()
 (255.0, 255.0, 255.0)

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 or tuples 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')
 >>> color("#285078", "#a0c8f0")
 >>> color()
 ((40.0, 80.0, 120.0), (160.0, 200.0, 240.0))

 See also: Screen method colormode(). Filling
turtle.filling()
Return fillstate (True if filling, False else).  >>> turtle.begin_fill()
 >>> if turtle.filling():
 ...    turtle.pensize(5)
 ... else:
 ...    turtle.pensize(3)

turtle.begin_fill()
To be called just before drawing a shape to be filled.

turtle.end_fill()
Fill the shape drawn after the last call to begin_fill(). Whether or not overlap regions for self-intersecting polygons or multiple shapes are filled depends on the operating system graphics, type of overlap, and number of overlaps. For example, the Turtle star above may be either all yellow or have some white regions. >>> turtle.color("black", "red")
>>> turtle.begin_fill()
>>> turtle.circle(80)
>>> turtle.end_fill()

 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.goto(0,-22)
>>> turtle.left(100)
>>> 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

arg – object to be written to the TurtleScreen
move – True/False
align – one of the strings “left”, “center” or right”
font – a triple (fontname, fontsize, fonttype)    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.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.hideturtle()

turtle.showturtle()
turtle.st()
Make the turtle visible. >>> turtle.showturtle()

turtle.isvisible()
Return True if the Turtle is shown, False if it’s hidden. >>> turtle.hideturtle()
>>> turtle.isvisible()
False
>>> turtle.showturtle()
>>> turtle.isvisible()
True

 Appearance
turtle.shape(name=None)
 Parameters
name – a string which is a valid shapename   Set turtle shape to shape with given name or, if name is not given, return name of current shape. Shape with name must exist in the TurtleScreen’s shape dictionary. Initially there are the following polygon shapes: “arrow”, “turtle”, “circle”, “square”, “triangle”, “classic”. To learn about how to deal with shapes see Screen method register_shape(). >>> turtle.shape()
'classic'
>>> turtle.shape("turtle")
>>> turtle.shape()
'turtle'

turtle.resizemode(rmode=None)
 Parameters
rmode – one of the strings “auto”, “user”, “noresize”   Set resizemode to one of the values: “auto”, “user”, “noresize”. If rmode is not given, return current resizemode. Different resizemodes have the following effects:  “auto”: adapts the appearance of the turtle corresponding to the value of pensize. “user”: adapts the appearance of the turtle according to the values of stretchfactor and outlinewidth (outline), which are set by 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("auto")
>>> turtle.resizemode()
'auto'

turtle.shapesize(stretch_wid=None, stretch_len=None, outline=None)
turtle.turtlesize(stretch_wid=None, stretch_len=None, outline=None)
 Parameters

stretch_wid – positive number
stretch_len – positive number
outline – positive number    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.shapesize()
(1.0, 1.0, 1)
>>> turtle.resizemode("user")
>>> turtle.shapesize(5, 5, 12)
>>> turtle.shapesize()
(5, 5, 12)
>>> turtle.shapesize(outline=8)
>>> turtle.shapesize()
(5, 5, 8)

turtle.shearfactor(shear=None)
 Parameters
shear – number (optional)   Set or return the current shearfactor. Shear the turtleshape according to the given shearfactor shear, which is the tangent of the shear angle. Do not change the turtle’s heading (direction of movement). If shear is not given: return the current shearfactor, i. e. the tangent of the shear angle, by which lines parallel to the heading of the turtle are sheared.  >>> turtle.shape("circle")
 >>> turtle.shapesize(5,2)
 >>> turtle.shearfactor(0.5)
 >>> turtle.shearfactor()
 0.5

turtle.tilt(angle)
 Parameters
angle – a number   Rotate the turtleshape by angle from its current tilt-angle, but do not change the turtle’s heading (direction of movement). >>> turtle.reset()
>>> turtle.shape("circle")
>>> turtle.shapesize(5,2)
>>> turtle.tilt(30)
>>> turtle.fd(50)
>>> turtle.tilt(30)
>>> turtle.fd(50)

turtle.settiltangle(angle)
 Parameters
angle – a number   Rotate the turtleshape to point in the direction specified by angle, regardless of its current tilt-angle. Do not change the turtle’s heading (direction of movement). >>> turtle.reset()
>>> turtle.shape("circle")
>>> turtle.shapesize(5,2)
>>> turtle.settiltangle(45)
>>> turtle.fd(50)
>>> turtle.settiltangle(-45)
>>> turtle.fd(50)
  Deprecated since version 3.1.

turtle.tiltangle(angle=None)
 Parameters
angle – a number (optional)   Set or return the current tilt-angle. If angle is given, 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). If angle is not given: 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.reset()
>>> turtle.shape("circle")
>>> turtle.shapesize(5,2)
>>> turtle.tilt(45)
>>> turtle.tiltangle()
45.0

turtle.shapetransform(t11=None, t12=None, t21=None, t22=None)
 Parameters

t11 – a number (optional)
t12 – a number (optional)
t21 – a number (optional)
t12 – a number (optional)    Set or return the current transformation matrix of the turtle shape. If none of the matrix elements are given, return the transformation matrix as a tuple of 4 elements. Otherwise set the given elements and transform the turtleshape according to the matrix consisting of first row t11, t12 and second row t21, t22. The determinant t11 * t22 - t12 * t21 must not be zero, otherwise an error is raised. Modify stretchfactor, shearfactor and tiltangle according to the given matrix. >>> turtle = Turtle()
>>> turtle.shape("square")
>>> turtle.shapesize(4,2)
>>> turtle.shearfactor(-0.5)
>>> turtle.shapetransform()
(4.0, -1.0, -0.0, 2.0)

turtle.get_shapepoly()
Return the current shape polygon as tuple of coordinate pairs. This can be used to define a new shape or components of a compound shape. >>> turtle.shape("square")
>>> turtle.shapetransform(4, -1, 0, 2)
>>> turtle.get_shapepoly()
((50, -20), (30, 20), (-50, 20), (-30, -20))

 Using events
turtle.onclick(fun, btn=1, add=None)
 Parameters

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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. >>> turtle.home()
>>> turtle.begin_poly()
>>> turtle.fd(100)
>>> turtle.left(20)
>>> turtle.fd(30)
>>> turtle.left(60)
>>> turtle.fd(50)
>>> turtle.end_poly()
>>> p = turtle.get_poly()
>>> 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()
turtle.getpen()
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 0x...>

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 0x...>
>>> ts.bgcolor("pink")

turtle.setundobuffer(size)
 Parameters
size – an integer or None   Set or disable undobuffer. If size is an integer, an empty undobuffer of given size is installed. size gives the maximum number of turtle actions that can be undone by the 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()

 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
args – a color string or three numbers in the range 0..colormode or a 3-tuple of such numbers   Set or return background color of the TurtleScreen. >>> screen.bgcolor("orange")
>>> screen.bgcolor()
'orange'
>>> screen.bgcolor("#800080")
>>> screen.bgcolor()
(128.0, 0.0, 128.0)

turtle.bgpic(picname=None)
 Parameters
picname – a string, name of a gif-file or "nopic", or None   Set background image or return name of current backgroundimage. If picname is a filename, set the corresponding image as background. If picname is "nopic", delete background image, if present. If picname is None, return the filename of the current backgroundimage. >>> screen.bgpic()
'nopic'
>>> screen.bgpic("landscape.gif")
>>> screen.bgpic()
"landscape.gif"

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 a different 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

canvwidth – positive integer, new width of canvas in pixels
canvheight – positive integer, new height of canvas in pixels
bg – colorstring or color-tuple, new background color    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. >>> screen.screensize()
(400, 300)
>>> screen.screensize(2000,1500)
>>> screen.screensize()
(2000, 1500)
 e.g. to search for an erroneously escaped turtle ;-)

turtle.setworldcoordinates(llx, lly, urx, ury)
 Parameters

llx – a number, x-coordinate of lower left corner of canvas
lly – a number, y-coordinate of lower left corner of canvas
urx – a number, x-coordinate of upper right corner of canvas
ury – a number, y-coordinate of upper right corner of canvas    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)
 Parameters
delay – positive integer   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()
10
>>> screen.delay(5)
>>> screen.delay()
5

turtle.tracer(n=None, delay=None)
 Parameters

n – nonnegative integer
delay – nonnegative integer    Turn turtle animation on/off and set delay for update drawings. If n is given, only each n-th regular screen update is really performed. (Can be used to accelerate the drawing of complex graphics.) When called without arguments, returns the currently stored value of n. 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)
turtle.onkeyrelease(fun, key)
 Parameters

fun – a function with no arguments or None

key – a string: key (e.g. “a”) or key-symbol (e.g. “space”)    Bind fun to key-release event of key. If fun is None, event bindings are removed. Remark: in order to be able to register key-events, TurtleScreen must have the focus. (See method listen().) >>> def f():
...     fd(50)
...     lt(60)
...
>>> screen.onkey(f, "Up")
>>> screen.listen()

turtle.onkeypress(fun, key=None)
 Parameters

fun – a function with no arguments or None

key – a string: key (e.g. “a”) or key-symbol (e.g. “space”)    Bind fun to key-press event of key if key is given, or to any key-press-event if no key is given. Remark: in order to be able to register key-events, TurtleScreen must have focus. (See method listen().) >>> def f():
...     fd(50)
...
>>> screen.onkey(f, "Up")
>>> screen.listen()

turtle.onclick(fun, btn=1, add=None)
turtle.onscreenclick(fun, btn=1, add=None)
 Parameters

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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

fun – a function with no arguments
t – a number >= 0    Install a timer that calls fun after t milliseconds. >>> running = True
>>> def f():
...     if running:
...         fd(50)
...         lt(60)
...         screen.ontimer(f, 250)
>>> f()   ### makes the turtle march around
>>> running = False

turtle.mainloop()
turtle.done()
Starts event loop - calling Tkinter’s mainloop function. Must be the last statement in a turtle graphics program. Must not be used if a script is run from within IDLE in -n mode (No subprocess) - for interactive use of turtle graphics. >>> screen.mainloop()

 Input methods
turtle.textinput(title, prompt)
 Parameters

title – string
prompt – string    Pop up a dialog window for input of a string. Parameter title is the title of the dialog window, prompt is a text mostly describing what information to input. Return the string input. If the dialog is canceled, return None. >>> screen.textinput("NIM", "Name of first player:")

turtle.numinput(title, prompt, default=None, minval=None, maxval=None)
 Parameters

title – string
prompt – string
default – number (optional)
minval – number (optional)
maxval – number (optional)    Pop up a dialog window for input of a number. title is the title of the dialog window, prompt is a text mostly describing what numerical information to input. default: default value, minval: minimum value for input, maxval: maximum value for input The number input must be in the range minval .. maxval if these are given. If not, a hint is issued and the dialog remains open for correction. Return the number input. If the dialog is canceled, return None. >>> screen.numinput("Poker", "Your stakes:", 1000, minval=10, maxval=10000)

 Settings and special methods
turtle.mode(mode=None)
 Parameters
mode – one of the strings “standard”, “logo” or “world”   Set turtle mode (“standard”, “logo” or “world”) and perform reset. If mode is not given, current mode is returned. Mode “standard” is compatible with old 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
cmode – one of the values 1.0 or 255   Return the colormode or set it to 1.0 or 255. Subsequently r, g, b values of color triples have to be in the range 0..cmode. >>> screen.colormode(1)
>>> turtle.pencolor(240, 160, 80)
Traceback (most recent call last):
     ...
TurtleGraphicsError: bad color sequence: (240, 160, 80)
>>> screen.colormode()
1.0
>>> screen.colormode(255)
>>> 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 object ...>

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. >>> screen.register_shape("turtle.gif")
  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. >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))

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).

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 dictionary and can be changed via a turtle.cfg file.  Parameters

width – if an integer, a size in pixels, if a float, a fraction of the screen; default is 50% of screen
height – if an integer, the height in pixels, if a float, a fraction of the screen; default is 75% of screen
startx – if positive, starting position in pixels from the left edge of the screen, if negative from the right edge, if None, center window horizontally
starty – if positive, starting position in pixels from the top edge of the screen, if negative from the bottom edge, if None, center window vertically    >>> 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
titlestring – a string that is shown in the titlebar of the turtle graphics window   Set title of turtle window to titlestring. >>> screen.title("Welcome to the turtle zoo!")

 Public classes
class turtle.RawTurtle(canvas)
class turtle.RawPen(canvas)
 Parameters
canvas – a tkinter.Canvas, a ScrolledCanvas or a TurtleScreen   Create a turtle. The turtle has all methods described above as “methods of Turtle/RawTurtle”.

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)
 Parameters
cv – a tkinter.Canvas   Provides screen oriented methods like setbg() etc. that are described above.

class turtle.Screen
Subclass of TurtleScreen, with four methods added.

class turtle.ScrolledCanvas(master)
 Parameters
master – some Tkinter widget to contain the ScrolledCanvas, i.e. a Tkinter-canvas with scrollbars added   Used by class Screen, which thus automatically provides a ScrolledCanvas as playground for the turtles.

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 compound shape has to be constructed using the addcomponent() method)
addcomponent(poly, fill, outline=None)
 Parameters

poly – a polygon, i.e. a tuple of pairs of numbers
fill – a color the poly will be filled with
outline – a color for the poly’s outline (if given)    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 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
filename – a string, used as filename   Create and write docstring-dictionary to a Python script with the given filename. This function has to be called explicitly (it is not used by the turtle graphics classes). The docstring dictionary will be written to the Python script filename.py. It is intended to serve as a template for translation of the docstrings into different languages.
 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.) How to configure Screen and Turtles The built-in default configuration mimics the appearance and behaviour of the old turtle module in order to retain best possible compatibility with it. If you want to use a different configuration which better reflects the features of this module or which better fits to your needs, e.g. for use in a classroom, you can prepare a configuration file turtle.cfg which will be read at import time and modify the configuration according to its settings. The built in configuration would correspond to the following turtle.cfg: width = 0.5
height = 0.75
leftright = None
topbottom = None
canvwidth = 400
canvheight = 300
mode = standard
colormode = 1.0
delay = 10
undobuffersize = 1000
shape = classic
pencolor = black
fillcolor = black
resizemode = noresize
visible = True
language = english
exampleturtle = turtle
examplescreen = screen
title = Python Turtle Graphics
using_IDLE = False
 Short explanation of selected entries:  The first four lines correspond to the arguments of the Screen.setup() method. Line 5 and 6 correspond to the arguments of the method Screen.screensize().
shape can be any of the built-in shapes, e.g: arrow, turtle, etc. For more info try help(shape). If you want to use no fillcolor (i.e. make the turtle transparent), you have to write fillcolor = "" (but all nonempty strings must not have quotes in the cfg-file). If you want to reflect the turtle its state, you have to use resizemode =
auto. If you set e.g. language = italian the docstringdict turtle_docstringdict_italian.py will be loaded at import time (if present on the import path, e.g. in the same directory as turtle. The entries exampleturtle and examplescreen define the names of these objects as they occur in the docstrings. The transformation of method-docstrings to function-docstrings will delete these names from the docstrings.
using_IDLE: Set this to True if you regularly work with IDLE and its -n switch (“no subprocess”). This will prevent exitonclick() to enter the mainloop.  There can be a turtle.cfg file in the directory where turtle is stored and an additional one in the current working directory. The latter will override the settings of the first one. The Lib/turtledemo directory contains a turtle.cfg file. You can study it as an example and see its effects when running the demos (preferably not from within the demo-viewer). turtledemo — Demo scripts The turtledemo package includes a set of demo scripts. These scripts can be run and viewed using the supplied demo viewer as follows: python -m turtledemo
 Alternatively, you can run the demo scripts individually. For example, python -m turtledemo.bytedesign
 The turtledemo package directory contains:  A demo viewer __main__.py which can be used to view the sourcecode of the scripts and run them at the same time. Multiple scripts demonstrating different features of the turtle module. Examples can be accessed via the Examples menu. They can also be run standalone. A turtle.cfg file which serves as an example of how to write and use such files.  The demo scripts are:
Name Description Features
bytedesign complex classical turtle graphics pattern tracer(), delay, update()
chaos graphs Verhulst dynamics, shows that computer’s computations can generate results sometimes against the common sense expectations world coordinates
clock analog clock showing time of your computer turtles as clock’s hands, ontimer
colormixer experiment with r, g, b ondrag()
forest 3 breadth-first trees randomization
fractalcurves Hilbert & Koch curves recursion
lindenmayer ethnomathematics (indian kolams) L-System
minimal_hanoi Towers of Hanoi Rectangular Turtles as Hanoi discs (shape, shapesize)
nim play the classical nim game with three heaps of sticks against the computer. turtles as nimsticks, event driven (mouse, keyboard)
paint super minimalistic drawing program onclick()
peace elementary turtle: appearance and animation
penrose aperiodic tiling with kites and darts stamp()
planet_and_moon simulation of gravitational system compound shapes, Vec2D
round_dance dancing turtles rotating pairwise in opposite direction compound shapes, clone shapesize, tilt, get_shapepoly, update
sorting_animate visual demonstration of different sorting methods simple alignment, randomization
tree a (graphical) breadth first tree (using generators) clone()
two_canvases simple design turtles on two canvases
wikipedia a pattern from the wikipedia article on turtle graphics clone(), undo()
yinyang another elementary example circle()   Have fun! Changes since Python 2.6  The methods Turtle.tracer(), Turtle.window_width() and Turtle.window_height() have been eliminated. Methods with these names and functionality are now available only as methods of Screen. The functions derived from these remain available. (In fact already in Python 2.6 these methods were merely duplications of the corresponding TurtleScreen/Screen-methods.) The method Turtle.fill() has been eliminated. The behaviour of begin_fill() and end_fill() have changed slightly: now every filling-process must be completed with an end_fill() call. A method Turtle.filling() has been added. It returns a boolean value: True if a filling process is under way, False otherwise. This behaviour corresponds to a fill() call without arguments in Python 2.6.  Changes since Python 3.0  The methods Turtle.shearfactor(), Turtle.shapetransform() and Turtle.get_shapepoly() have been added. Thus the full range of regular linear transforms is now available for transforming turtle shapes. Turtle.tiltangle() has been enhanced in functionality: it now can be used to get or set the tiltangle. Turtle.settiltangle() has been deprecated. The method Screen.onkeypress() has been added as a complement to Screen.onkey() which in fact binds actions to the keyrelease event. Accordingly the latter has got an alias: Screen.onkeyrelease(). The method Screen.mainloop() has been added. So when working only with Screen and Turtle objects one must not additionally import mainloop() anymore. Two input methods has been added Screen.textinput() and Screen.numinput(). These popup input dialogs and return strings and numbers respectively. Two example scripts tdemo_nim.py and tdemo_round_dance.py have been added to the Lib/turtledemo directory.


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. >>> screen.register_shape("turtle.gif")
  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. >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))

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).


turtle.back(distance)
turtle.bk(distance)
turtle.backward(distance)
 Parameters
distance – a number   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.begin_fill()
To be called just before drawing a shape to be filled.


turtle.begin_poly()
Start recording the vertices of a polygon. Current turtle position is first vertex of polygon.


turtle.bgcolor(*args)
 Parameters
args – a color string or three numbers in the range 0..colormode or a 3-tuple of such numbers   Set or return background color of the TurtleScreen. >>> screen.bgcolor("orange")
>>> screen.bgcolor()
'orange'
>>> screen.bgcolor("#800080")
>>> screen.bgcolor()
(128.0, 0.0, 128.0)


turtle.bgpic(picname=None)
 Parameters
picname – a string, name of a gif-file or "nopic", or None   Set background image or return name of current backgroundimage. If picname is a filename, set the corresponding image as background. If picname is "nopic", delete background image, if present. If picname is None, return the filename of the current backgroundimage. >>> screen.bgpic()
'nopic'
>>> screen.bgpic("landscape.gif")
>>> screen.bgpic()
"landscape.gif"


turtle.bye()
Shut the turtlegraphics window.


turtle.circle(radius, extent=None, steps=None)
 Parameters

radius – a number
extent – a number (or None)
steps – an integer (or None)    Draw a circle with given radius. The center is radius units left of the turtle; extent – an angle – determines which part of the circle is drawn. If extent is not given, draw the entire circle. If extent is not a full circle, one endpoint of the arc is the current pen position. Draw the arc in counterclockwise direction if radius is positive, otherwise in clockwise direction. Finally the direction of the turtle is changed by the amount of extent. As the circle is approximated by an inscribed regular polygon, steps determines the number of steps to use. If not given, it will be calculated automatically. May be used to draw regular polygons. >>> turtle.home()
>>> turtle.position()
(0.00,0.00)
>>> turtle.heading()
0.0
>>> turtle.circle(50)
>>> turtle.position()
(-0.00,0.00)
>>> turtle.heading()
0.0
>>> turtle.circle(120, 180)  # draw a semicircle
>>> turtle.position()
(0.00,240.00)
>>> turtle.heading()
180.0


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 a different one derived from the Turtle method clear.


turtle.clearstamp(stampid)
 Parameters
stampid – an integer, must be return value of previous stamp() call   Delete stamp with given stampid. >>> turtle.position()
(150.00,-0.00)
>>> turtle.color("blue")
>>> astamp = turtle.stamp()
>>> turtle.fd(50)
>>> turtle.position()
(200.00,-0.00)
>>> turtle.clearstamp(astamp)
>>> turtle.position()
(200.00,-0.00)


turtle.clearstamps(n=None)
 Parameters
n – an integer (or None)   Delete all or first/last n of turtle’s stamps. If n is None, delete all stamps, if n > 0 delete first n stamps, else if n < 0 delete last n stamps. >>> for i in range(8):
...     turtle.stamp(); turtle.fd(30)
13
14
15
16
17
18
19
20
>>> turtle.clearstamps(2)
>>> turtle.clearstamps(-2)
>>> turtle.clearstamps()


turtle.clone()
Create and return a clone of the turtle with same position, heading and turtle properties. >>> mick = Turtle()
>>> joe = mick.clone()


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 or tuples 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')
 >>> color("#285078", "#a0c8f0")
 >>> color()
 ((40.0, 80.0, 120.0), (160.0, 200.0, 240.0))


turtle.colormode(cmode=None)
 Parameters
cmode – one of the values 1.0 or 255   Return the colormode or set it to 1.0 or 255. Subsequently r, g, b values of color triples have to be in the range 0..cmode. >>> screen.colormode(1)
>>> turtle.pencolor(240, 160, 80)
Traceback (most recent call last):
     ...
TurtleGraphicsError: bad color sequence: (240, 160, 80)
>>> screen.colormode()
1.0
>>> screen.colormode(255)
>>> screen.colormode()
255
>>> turtle.pencolor(240,160,80)


turtle.degrees(fullcircle=360.0)
 Parameters
fullcircle – a number   Set angle measurement units, i.e. set number of “degrees” for a full circle. Default value is 360 degrees. >>> turtle.home()
>>> turtle.left(90)
>>> turtle.heading()
90.0

Change angle measurement unit to grad (also known as gon,
grade, or gradian and equals 1/100-th of the right angle.)
>>> turtle.degrees(400.0)
>>> turtle.heading()
100.0
>>> turtle.degrees(360)
>>> turtle.heading()
90.0


turtle.delay(delay=None)
 Parameters
delay – positive integer   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()
10
>>> screen.delay(5)
>>> screen.delay()
5


turtle.distance(x, y=None)
 Parameters

x – a number or a pair/vector of numbers or a turtle instance
y – a number if x is a number, else None
    Return the distance from the turtle to (x,y), the given vector, or the given other turtle, in turtle step units. >>> turtle.home()
>>> turtle.distance(30,40)
50.0
>>> turtle.distance((30,40))
50.0
>>> joe = Turtle()
>>> joe.forward(77)
>>> turtle.distance(joe)
77.0


turtle.mainloop()
turtle.done()
Starts event loop - calling Tkinter’s mainloop function. Must be the last statement in a turtle graphics program. Must not be used if a script is run from within IDLE in -n mode (No subprocess) - for interactive use of turtle graphics. >>> screen.mainloop()


turtle.dot(size=None, *color)
 Parameters

size – an integer >= 1 (if given)
color – a colorstring or a numeric color tuple    Draw a circular dot with diameter size, using color. If size is not given, the maximum of pensize+4 and 2*pensize is used. >>> turtle.home()
>>> turtle.dot()
>>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50)
>>> turtle.position()
(100.00,-0.00)
>>> turtle.heading()
0.0


turtle.pendown()
turtle.pd()
turtle.down()
Pull the pen down – drawing when moving.


turtle.end_fill()
Fill the shape drawn after the last call to begin_fill(). Whether or not overlap regions for self-intersecting polygons or multiple shapes are filled depends on the operating system graphics, type of overlap, and number of overlaps. For example, the Turtle star above may be either all yellow or have some white regions. >>> turtle.color("black", "red")
>>> turtle.begin_fill()
>>> turtle.circle(80)
>>> turtle.end_fill()


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.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.forward(distance)
turtle.fd(distance)
 Parameters
distance – a number (integer or float)   Move the turtle forward by the specified distance, in the direction the turtle is headed. >>> turtle.position()
(0.00,0.00)
>>> turtle.forward(25)
>>> turtle.position()
(25.00,0.00)
>>> turtle.forward(-75)
>>> turtle.position()
(-50.00,0.00)


turtle.fillcolor(*args)
Return or set the fillcolor. Four input formats are allowed:
fillcolor()

Return the current fillcolor as color specification string, possibly in tuple 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")
 >>> turtle.fillcolor()
 'violet'
 >>> turtle.pencolor()
 (50.0, 193.0, 143.0)
 >>> turtle.fillcolor((50, 193, 143))  # Integers, not floats
 >>> turtle.fillcolor()
 (50.0, 193.0, 143.0)
 >>> turtle.fillcolor('#ffffff')
 >>> turtle.fillcolor()
 (255.0, 255.0, 255.0)


turtle.filling()
Return fillstate (True if filling, False else).  >>> turtle.begin_fill()
 >>> if turtle.filling():
 ...    turtle.pensize(5)
 ... else:
 ...    turtle.pensize(3)


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 object ...>


turtle.getturtle()
turtle.getpen()
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 0x...>


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 0x...>
>>> ts.bgcolor("pink")


turtle.getshapes()
Return a list of names of all currently available turtle shapes. >>> screen.getshapes()
['arrow', 'blank', 'circle', ..., 'turtle']


turtle.get_poly()
Return the last recorded polygon. >>> turtle.home()
>>> turtle.begin_poly()
>>> turtle.fd(100)
>>> turtle.left(20)
>>> turtle.fd(30)
>>> turtle.left(60)
>>> turtle.fd(50)
>>> turtle.end_poly()
>>> p = turtle.get_poly()
>>> register_shape("myFavouriteShape", p)


turtle.get_shapepoly()
Return the current shape polygon as tuple of coordinate pairs. This can be used to define a new shape or components of a compound shape. >>> turtle.shape("square")
>>> turtle.shapetransform(4, -1, 0, 2)
>>> turtle.get_shapepoly()
((50, -20), (30, 20), (-50, 20), (-30, -20))


turtle.goto(x, y=None)
turtle.setpos(x, y=None)
turtle.setposition(x, y=None)
 Parameters

x – a number or a pair/vector of numbers
y – a number or None
    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.heading()
Return the turtle’s current heading (value depends on the turtle mode, see mode()). >>> turtle.home()
>>> turtle.left(67)
>>> turtle.heading()
67.0


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.hideturtle()


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.heading()
90.0
>>> turtle.position()
(0.00,-10.00)
>>> turtle.home()
>>> turtle.position()
(0.00,0.00)
>>> turtle.heading()
0.0


turtle.isdown()
Return True if pen is down, False if it’s up. >>> turtle.penup()
>>> turtle.isdown()
False
>>> turtle.pendown()
>>> turtle.isdown()
True


turtle.isvisible()
Return True if the Turtle is shown, False if it’s hidden. >>> turtle.hideturtle()
>>> turtle.isvisible()
False
>>> turtle.showturtle()
>>> turtle.isvisible()
True


turtle.left(angle)
turtle.lt(angle)
 Parameters
angle – a 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.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.mainloop()
turtle.done()
Starts event loop - calling Tkinter’s mainloop function. Must be the last statement in a turtle graphics program. Must not be used if a script is run from within IDLE in -n mode (No subprocess) - for interactive use of turtle graphics. >>> screen.mainloop()


turtle.mode(mode=None)
 Parameters
mode – one of the strings “standard”, “logo” or “world”   Set turtle mode (“standard”, “logo” or “world”) and perform reset. If mode is not given, current mode is returned. Mode “standard” is compatible with old 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.numinput(title, prompt, default=None, minval=None, maxval=None)
 Parameters

title – string
prompt – string
default – number (optional)
minval – number (optional)
maxval – number (optional)    Pop up a dialog window for input of a number. title is the title of the dialog window, prompt is a text mostly describing what numerical information to input. default: default value, minval: minimum value for input, maxval: maximum value for input The number input must be in the range minval .. maxval if these are given. If not, a hint is issued and the dialog remains open for correction. Return the number input. If the dialog is canceled, return None. >>> screen.numinput("Poker", "Your stakes:", 1000, minval=10, maxval=10000)


turtle.onclick(fun, btn=1, add=None)
turtle.onscreenclick(fun, btn=1, add=None)
 Parameters

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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.ondrag(fun, btn=1, add=None)
 Parameters

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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).


turtle.onkey(fun, key)
turtle.onkeyrelease(fun, key)
 Parameters

fun – a function with no arguments or None

key – a string: key (e.g. “a”) or key-symbol (e.g. “space”)    Bind fun to key-release event of key. If fun is None, event bindings are removed. Remark: in order to be able to register key-events, TurtleScreen must have the focus. (See method listen().) >>> def f():
...     fd(50)
...     lt(60)
...
>>> screen.onkey(f, "Up")
>>> screen.listen()


turtle.onkeypress(fun, key=None)
 Parameters

fun – a function with no arguments or None

key – a string: key (e.g. “a”) or key-symbol (e.g. “space”)    Bind fun to key-press event of key if key is given, or to any key-press-event if no key is given. Remark: in order to be able to register key-events, TurtleScreen must have focus. (See method listen().) >>> def f():
...     fd(50)
...
>>> screen.onkey(f, "Up")
>>> screen.listen()


turtle.onrelease(fun, btn=1, add=None)
 Parameters

fun – a function with two arguments which will be called with the coordinates of the clicked point on the canvas
btn – number of the mouse-button, defaults to 1 (left mouse button)
add – True or False – if True, a new binding will be added, otherwise it will replace a former binding    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.ontimer(fun, t=0)
 Parameters

fun – a function with no arguments
t – a number >= 0    Install a timer that calls fun after t milliseconds. >>> running = True
>>> def f():
...     if running:
...         fd(50)
...         lt(60)
...         screen.ontimer(f, 250)
>>> f()   ### makes the turtle march around
>>> running = False


turtle.pendown()
turtle.pd()
turtle.down()
Pull the pen down – drawing when moving.


turtle.pen(pen=None, **pendict)
 Parameters

pen – a dictionary with some or all of the below listed keys
pendict – one or more keyword-arguments with the below listed keys as keywords    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 dictionary 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)
>>> sorted(turtle.pen().items())
[('fillcolor', 'black'), ('outline', 1), ('pencolor', 'red'),
 ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'),
 ('shearfactor', 0.0), ('shown', True), ('speed', 9),
 ('stretchfactor', (1.0, 1.0)), ('tilt', 0.0)]
>>> penstate=turtle.pen()
>>> turtle.color("yellow", "")
>>> turtle.penup()
>>> sorted(turtle.pen().items())[:3]
[('fillcolor', ''), ('outline', 1), ('pencolor', 'yellow')]
>>> turtle.pen(penstate, fillcolor="green")
>>> sorted(turtle.pen().items())[:3]
[('fillcolor', 'green'), ('outline', 1), ('pencolor', 'red')]


turtle.pencolor(*args)
Return or set the pencolor. Four input formats are allowed:
pencolor()

Return the current pencolor as color specification string or as a tuple (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.  >>> colormode()
 1.0
 >>> turtle.pencolor()
 'red'
 >>> turtle.pencolor("brown")
 >>> turtle.pencolor()
 'brown'
 >>> tup = (0.2, 0.8, 0.55)
 >>> turtle.pencolor(tup)
 >>> turtle.pencolor()
 (0.2, 0.8, 0.5490196078431373)
 >>> colormode(255)
 >>> turtle.pencolor()
 (51.0, 204.0, 140.0)
 >>> turtle.pencolor('#32c18f')
 >>> turtle.pencolor()
 (50.0, 193.0, 143.0)


turtle.pensize(width=None)
turtle.width(width=None)
 Parameters
width – a positive number   Set the line thickness to width or return it. If resizemode is set to “auto” and turtleshape is a polygon, that polygon is drawn with the same line thickness. If no argument is given, the current pensize is returned. >>> turtle.pensize()
1
>>> turtle.pensize(10)   # from here on lines of width 10 are drawn


turtle.penup()
turtle.pu()
turtle.up()
Pull the pen up – no drawing when moving.


turtle.position()
turtle.pos()
Return the turtle’s current location (x,y) (as a Vec2D vector). >>> turtle.pos()
(440.00,-0.00)


turtle.radians()
Set the angle measurement units to radians. Equivalent to degrees(2*math.pi). >>> turtle.home()
>>> turtle.left(90)
>>> turtle.heading()
90.0
>>> turtle.radians()
>>> turtle.heading()
1.5707963267948966


class turtle.RawTurtle(canvas)
class turtle.RawPen(canvas)
 Parameters
canvas – a tkinter.Canvas, a ScrolledCanvas or a TurtleScreen   Create a turtle. The turtle has all methods described above as “methods of Turtle/RawTurtle”.


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. >>> screen.register_shape("turtle.gif")
  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. >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))

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).


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.resizemode(rmode=None)
 Parameters
rmode – one of the strings “auto”, “user”, “noresize”   Set resizemode to one of the values: “auto”, “user”, “noresize”. If rmode is not given, return current resizemode. Different resizemodes have the following effects:  “auto”: adapts the appearance of the turtle corresponding to the value of pensize. “user”: adapts the appearance of the turtle according to the values of stretchfactor and outlinewidth (outline), which are set by 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("auto")
>>> turtle.resizemode()
'auto'


turtle.right(angle)
turtle.rt(angle)
 Parameters
angle – a 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


class turtle.Screen
Subclass of TurtleScreen, with four methods added.


turtle.screensize(canvwidth=None, canvheight=None, bg=None)
 Parameters

canvwidth – positive integer, new width of canvas in pixels
canvheight – positive integer, new height of canvas in pixels
bg – colorstring or color-tuple, new background color    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. >>> screen.screensize()
(400, 300)
>>> screen.screensize(2000,1500)
>>> screen.screensize()
(2000, 1500)
 e.g. to search for an erroneously escaped turtle ;-)


class turtle.ScrolledCanvas(master)
 Parameters
master – some Tkinter widget to contain the ScrolledCanvas, i.e. a Tkinter-canvas with scrollbars added   Used by class Screen, which thus automatically provides a ScrolledCanvas as playground for the turtles.


turtle.setheading(to_angle)
turtle.seth(to_angle)
 Parameters
to_angle – a number (integer or float)   Set the orientation of the turtle to to_angle. Here are some common directions in degrees:
standard mode logo mode
0 - east 0 - north
90 - north 90 - east
180 - west 180 - south
270 - south 270 - west   >>> turtle.setheading(90)
>>> turtle.heading()
90.0


turtle.goto(x, y=None)
turtle.setpos(x, y=None)
turtle.setposition(x, y=None)
 Parameters

x – a number or a pair/vector of numbers
y – a number or None
    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.settiltangle(angle)
 Parameters
angle – a number   Rotate the turtleshape to point in the direction specified by angle, regardless of its current tilt-angle. Do not change the turtle’s heading (direction of movement). >>> turtle.reset()
>>> turtle.shape("circle")
>>> turtle.shapesize(5,2)
>>> turtle.settiltangle(45)
>>> turtle.fd(50)
>>> turtle.settiltangle(-45)
>>> turtle.fd(50)
  Deprecated since version 3.1.


turtle.setundobuffer(size)
 Parameters
size – an integer or None   Set or disable undobuffer. If size is an integer, an empty undobuffer of given size is installed. size gives the maximum number of turtle actions that can be undone by the undo() method/function. If size is None, the undobuffer is disabled. >>> turtle.setundobuffer(42)


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 dictionary and can be changed via a turtle.cfg file.  Parameters

width – if an integer, a size in pixels, if a float, a fraction of the screen; default is 50% of screen
height – if an integer, the height in pixels, if a float, a fraction of the screen; default is 75% of screen
startx – if positive, starting position in pixels from the left edge of the screen, if negative from the right edge, if None, center window horizontally
starty – if positive, starting position in pixels from the top edge of the screen, if negative from the bottom edge, if None, center window vertically    >>> 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.setworldcoordinates(llx, lly, urx, ury)
 Parameters

llx – a number, x-coordinate of lower left corner of canvas
lly – a number, y-coordinate of lower left corner of canvas
urx – a number, x-coordinate of upper right corner of canvas
ury – a number, y-coordinate of upper right corner of canvas    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


turtle.setx(x)
 Parameters
x – a number (integer or float)   Set the turtle’s first coordinate to x, leave second coordinate unchanged. >>> turtle.position()
(0.00,240.00)
>>> turtle.setx(10)
>>> turtle.position()
(10.00,240.00)


turtle.sety(y)
 Parameters
y – a number (integer or float)   Set the turtle’s second coordinate to y, leave first coordinate unchanged. >>> turtle.position()
(0.00,40.00)
>>> turtle.sety(-10)
>>> turtle.position()
(0.00,-10.00)


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 compound shape has to be constructed using the addcomponent() method)
addcomponent(poly, fill, outline=None)
 Parameters

poly – a polygon, i.e. a tuple of pairs of numbers
fill – a color the poly will be filled with
outline – a color for the poly’s outline (if given)    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 Compound shapes.


turtle.shape(name=None)
 Parameters
name – a string which is a valid shapename   Set turtle shape to shape with given name or, if name is not given, return name of current shape. Shape with name must exist in the TurtleScreen’s shape dictionary. Initially there are the following polygon shapes: “arrow”, “turtle”, “circle”, “square”, “triangle”, “classic”. To learn about how to deal with shapes see Screen method register_shape(). >>> turtle.shape()
'classic'
>>> turtle.shape("turtle")
>>> turtle.shape()
'turtle'


addcomponent(poly, fill, outline=None)
 Parameters

poly – a polygon, i.e. a tuple of pairs of numbers
fill – a color the poly will be filled with
outline – a color for the poly’s outline (if given)    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 Compound shapes.


turtle.shapesize(stretch_wid=None, stretch_len=None, outline=None)
turtle.turtlesize(stretch_wid=None, stretch_len=None, outline=None)
 Parameters

stretch_wid – positive number
stretch_len – positive number
outline – positive number    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.shapesize()
(1.0, 1.0, 1)
>>> turtle.resizemode("user")
>>> turtle.shapesize(5, 5, 12)
>>> turtle.shapesize()
(5, 5, 12)
>>> turtle.shapesize(outline=8)
>>> turtle.shapesize()
(5, 5, 8)


turtle.shapetransform(t11=None, t12=None, t21=None, t22=None)
 Parameters

t11 – a number (optional)
t12 – a number (optional)
t21 – a number (optional)
t12 – a number (optional)    Set or return the current transformation matrix of the turtle shape. If none of the matrix elements are given, return the transformation matrix as a tuple of 4 elements. Otherwise set the given elements and transform the turtleshape according to the matrix consisting of first row t11, t12 and second row t21, t22. The determinant t11 * t22 - t12 * t21 must not be zero, otherwise an error is raised. Modify stretchfactor, shearfactor and tiltangle according to the given matrix. >>> turtle = Turtle()
>>> turtle.shape("square")
>>> turtle.shapesize(4,2)
>>> turtle.shearfactor(-0.5)
>>> turtle.shapetransform()
(4.0, -1.0, -0.0, 2.0)


turtle.shearfactor(shear=None)
 Parameters
shear – number (optional)   Set or return the current shearfactor. Shear the turtleshape according to the given shearfactor shear, which is the tangent of the shear angle. Do not change the turtle’s heading (direction of movement). If shear is not given: return the current shearfactor, i. e. the tangent of the shear angle, by which lines parallel to the heading of the turtle are sheared.  >>> turtle.shape("circle")
 >>> turtle.shapesize(5,2)
 >>> turtle.shearfactor(0.5)
 >>> turtle.shearfactor()
 0.5


turtle.showturtle()
turtle.st()
Make the turtle visible. >>> turtle.showturtle()


turtle.speed(speed=None)
 Parameters
speed – an integer in the range 0..10 or a speedstring (see below)   Set the turtle’s speed to an integer value in the range 0..10. If no argument is given, return current speed. If input is a number greater than 10 or smaller than 0.5, speed is set to 0. Speedstrings are mapped to speedvalues as follows:  “fastest”: 0 “fast”: 10 “normal”: 6 “slow”: 3 “slowest”: 1  Speeds from 1 to 10 enforce increasingly faster animation of line drawing and turtle turning. Attention: speed = 0 means that no animation takes place. forward/back makes turtle jump and likewise left/right make the turtle turn instantly. >>> turtle.speed()
3
>>> turtle.speed('normal')
>>> turtle.speed()
6
>>> turtle.speed(9)
>>> turtle.speed()
9


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()
11
>>> turtle.fd(50)


turtle.textinput(title, prompt)
 Parameters

title – string
prompt – string    Pop up a dialog window for input of a string. Parameter title is the title of the dialog window, prompt is a text mostly describing what information to input. Return the string input. If the dialog is canceled, return None. >>> screen.textinput("NIM", "Name of first player:")


turtle.tilt(angle)
 Parameters
angle – a number   Rotate the turtleshape by angle from its current tilt-angle, but do not change the turtle’s heading (direction of movement). >>> turtle.reset()
>>> turtle.shape("circle")
>>> turtle.shapesize(5,2)
>>> turtle.tilt(30)
>>> turtle.fd(50)
>>> turtle.tilt(30)
>>> turtle.fd(50)


turtle.tiltangle(angle=None)
 Parameters
angle – a number (optional)   Set or return the current tilt-angle. If angle is given, 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). If angle is not given: 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.reset()
>>> turtle.shape("circle")
>>> turtle.shapesize(5,2)
>>> turtle.tilt(45)
>>> turtle.tiltangle()
45.0


turtle.title(titlestring)
 Parameters
titlestring – a string that is shown in the titlebar of the turtle graphics window   Set title of turtle window to titlestring. >>> screen.title("Welcome to the turtle zoo!")


turtle.towards(x, y=None)
 Parameters

x – a number or a pair/vector of numbers or a turtle instance
y – a number if x is a number, else None
    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.goto(10, 10)
>>> turtle.towards(0,0)
225.0


turtle.tracer(n=None, delay=None)
 Parameters

n – nonnegative integer
delay – nonnegative integer    Turn turtle animation on/off and set delay for update drawings. If n is given, only each n-th regular screen update is really performed. (Can be used to accelerate the drawing of complex graphics.) When called without arguments, returns the currently stored value of n. Second argument sets delay value (see delay()). >>> screen.tracer(8, 25)
>>> dist = 2
>>> for i in range(200):
...     fd(dist)
...     rt(90)
...     dist += 2


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.


turtle.turtles()
Return the list of turtles on the screen. >>> for turtle in screen.turtles():
...     turtle.color("red")


class turtle.TurtleScreen(cv)
 Parameters
cv – a tkinter.Canvas   Provides screen oriented methods like setbg() etc. that are described above.


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.undobufferentries()
Return number of entries in the undobuffer. >>> while undobufferentries():
...     undo()


turtle.penup()
turtle.pu()
turtle.up()
Pull the pen up – no drawing when moving.


turtle.update()
Perform a TurtleScreen update. To be used when tracer is turned off.


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


turtle.pensize(width=None)
turtle.width(width=None)
 Parameters
width – a positive number   Set the line thickness to width or return it. If resizemode is set to “auto” and turtleshape is a polygon, that polygon is drawn with the same line thickness. If no argument is given, the current pensize is returned. >>> turtle.pensize()
1
>>> turtle.pensize(10)   # from here on lines of width 10 are drawn


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


turtle.write(arg, move=False, align="left", font=("Arial", 8, "normal"))
 Parameters

arg – object to be written to the TurtleScreen
move – True/False
align – one of the strings “left”, “center” or right”
font – a triple (fontname, fontsize, fonttype)    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.write_docstringdict(filename="turtle_docstringdict")
 Parameters
filename – a string, used as filename   Create and write docstring-dictionary to a Python script with the given filename. This function has to be called explicitly (it is not used by the turtle graphics classes). The docstring dictionary will be written to the Python script filename.py. It is intended to serve as a template for translation of the docstrings into different languages.


turtle.xcor()
Return the turtle’s x coordinate. >>> turtle.home()
>>> turtle.left(50)
>>> turtle.forward(100)
>>> turtle.pos()
(64.28,76.60)
>>> print(round(turtle.xcor(), 5))
64.27876


turtle.ycor()
Return the turtle’s y coordinate. >>> turtle.home()
>>> turtle.left(60)
>>> turtle.forward(100)
>>> print(turtle.pos())
(50.00,86.60)
>>> print(round(turtle.ycor(), 5))
86.60254


class type(object)
class type(name, bases, dict, **kwds)
With one argument, return the type of an object. The return value is a type object and generally the same object as returned by object.__class__. The isinstance() built-in function is recommended for testing the type of an object, because it takes subclasses into account. With three arguments, return a new type object. This is essentially a dynamic form of the class statement. The name string is the class name and becomes the __name__ attribute. The bases tuple contains the base classes and becomes the __bases__ attribute; if empty, object, the ultimate base of all classes, is added. The dict dictionary contains attribute and method definitions for the class body; it may be copied or wrapped before becoming the __dict__ attribute. The following two statements create identical type objects: >>> class X:
...     a = 1
...
>>> X = type('X', (), dict(a=1))
 See also Type Objects. Keyword arguments provided to the three argument form are passed to the appropriate metaclass machinery (usually __init_subclass__()) in the same way that keywords in a class definition (besides metaclass) would. See also Customizing class creation.  Changed in version 3.6: Subclasses of type which don’t override type.__new__ may no longer use the one-argument form to get the type of an object.


exception TypeError
Raised when an operation or function is applied to an object of inappropriate type. The associated value is a string giving details about the type mismatch. This exception may be raised by user code to indicate that an attempted operation on an object is not supported, and is not meant to be. If an object is meant to support a given operation but has not yet provided an implementation, NotImplementedError is the proper exception to raise. Passing arguments of the wrong type (e.g. passing a list when an int is expected) should result in a TypeError, but passing arguments with the wrong value (e.g. a number outside expected boundaries) should result in a ValueError.