turtle
— Turtle graphics¶Note
The turtle
module that comes with Pythonista is not 100% compatible with the standard library version because it’s based on the ui
module rather than Tkinter
(which isn’t available in Pythonista). It should work just fine for learning, but some advanced features (like mouse/keyboard interaction) are not implemented. For typical (educational) use cases, this should not be a problem. This documentation page has been edited to remove references to features that are not available in Pythonista, but the rest is mostly unchanged.
Turtle graphics is a popular way for introducing programming to kids. It was part of the original Logo programming language developed by Wally Feurzig and Seymour Papert in 1966.
Imagine a robotic turtle starting at (0, 0) in the xy plane. After an import turtle
, give it the
command turtle.forward(15)
, and it moves (onscreen!) 15 pixels in the
direction it is facing, drawing a line as it moves. Give it the command
turtle.right(25)
, and it rotates inplace 25 degrees clockwise.
By combining together these and similar commands, intricate shapes and pictures can easily be drawn.
The turtle
module is an extended reimplementation of the samenamed
module from the Python standard distribution up to version Python 2.5.
The turtle module provides turtle graphics primitives, in both objectoriented and procedureoriented ways.
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 objectoriented 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.
shape()
resizemode()
shapesize()
 turtlesize()
shearfactor()
settiltangle()
tiltangle()
tilt()
shapetransform()
get_shapepoly()
onclick()
onrelease()
ondrag()
begin_poly()
end_poly()
get_poly()
setundobuffer()
undobufferentries()
listen()
onkey()
 onkeyrelease()
onkeypress()
onclick()
 onscreenclick()
ontimer()
mainloop()
 done()
mode()
getcanvas()
getshapes()
register_shape()
 addshape()
Most of the examples in this section refer to a Turtle instance called
turtle
.
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: 


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 startorientation (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: 


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: 


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.
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:
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.
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: 


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: 


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.
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 1/100th 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
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: 


Return or set the pen’s attributes in a “pendictionary” with the following key/value pairs:
Note
resizemode, outline, tilt, and stretchfactor are not supported in Pythonista.
This dictionary can be used as argument for a subsequent call to pen()
to restore the former penstate. Moreover one or more of these attributes
can be provided as keywordarguments. 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
turtle.
pencolor
(*args)¶Return or set the pencolor.
Four input formats are allowed:
pencolor()
pencolor(colorstring)
"red"
, "yellow"
, or "#33cc8c"
.pencolor((r, g, b))
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()
fillcolor(colorstring)
"red"
, "yellow"
, or "#33cc8c"
.fillcolor((r, g, b))
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'
>>> col = turtle.pencolor()
>>> col
(50.0, 193.0, 143.0)
>>> turtle.fillcolor(col)
>>> 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()
pencolor()
and
fillcolor()
.color(colorstring)
, color((r,g,b))
, color(r,g,b)
pencolor()
, set both, fillcolor and pencolor, to the
given value.color(colorstring1, colorstring2)
, color((r1,g1,b1), (r2,g2,b2))
Equivalent topencolor(colorstring1)
andfillcolor(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: colormode()
.
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()
.
>>> turtle.color("black", "red")
>>> turtle.begin_fill()
>>> turtle.circle(80)
>>> turtle.end_fill()
turtle.
reset
()¶Delete the turtle’s drawings from the screen, recenter 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: 


Note
The align and font arguments are not supported in Pythonista.
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 bottomright corner of the
text. By default, move is False
.
>>> turtle.write("Home = ", True, align="center")
>>> turtle.write((0,0), True)
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.
isvisible
()¶Return True
if the Turtle is shown, False
if it’s hidden.
>>> turtle.hideturtle()
>>> turtle.isvisible()
False
>>> turtle.showturtle()
>>> turtle.isvisible()
True
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.
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: 


Turn turtle animation on/off and set delay for update drawings. If
n is given, only each nth 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
See also the RawTurtle/Turtle method speed()
.
turtle.
textinput
(title, prompt)¶Parameters: 


Pop up a dialog window for input of a string. Parameter title is the title of the dialog window, propmt 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: 


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.
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.
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
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: 


>>> 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!")
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.
Vec2D
(x, y)¶A twodimensional 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 additiona  b
vector subtractiona * b
inner productk * a
and a * k
multiplication with scalarabs(a)
absolute value of aa.rotate(angle)
rotation