# 3.14. A Few More `turtle` Methods and Observations¶

Here is a table that summarizes common Turtle methods:

Method

Parameters

Description

Turtle

None

Creates and returns a new turtle object

forward

distance

Moves the turtle forward

backward

distance

Moves the turle backward

right

angle

Turns the turtle clockwise

left

angle

Turns the turtle counter clockwise

up

None

Picks up the turtle’s tail (pen)

down

None

Puts down the turtle’s tail (pen)

color

color name

Changes the color of the turtle and pen

fillcolor

color name

Changes the color the turtle will use to fill a polygon

None

position

None

Returns the current position

goto

x,y

Move the turtle to position x,y

begin_fill

None

Remember the starting point for a filled polygon

end_fill

None

Close the polygon and fill with the current fill color

dot

None

Leave a dot at the current position

stamp

None

Leaves an impression of a turtle shape at the current location

shape

shapename

Can be set to ‘arrow’, ‘triangle’, ‘classic’, ‘turtle’, ‘circle’, or ‘square’

speed

integer

0 = no animation, fastest; 1 = slowest; 10 = very fast

Here are a few more things that you might find useful as you write programs that use turtles.

• Turtle methods can use negative angles or distances. So `tess.forward(-100)` will move tess backwards, and `tess.left(-30)` turns her to the right. Additionally, because there are 360 degrees in a circle, turning 30 to the left will leave you facing in the same direction as turning 330 to the right! (The on-screen animation will differ, though — you will be able to tell if tess is turning clockwise or counter-clockwise!)

This suggests that we don’t need both a left and a right turn method — we could be minimalists, and just have one method. There is also a backward method. (If you are very nerdy, you might enjoy saying `alex.backward(-100)` to move alex forward!)

Reviewing a few basic facts about geometry and number lines, like we’ve done here, is a good start if we’re going to play with turtles.

• A turtle’s pen can be picked up or put down. This allows us to move a turtle to a different place without drawing a line. The methods are `up` and `down`. Note that the methods `penup` and `pendown` do the same thing.

```alex.up()
alex.forward(100)     # this moves alex, but no line is drawn
alex.down()
```
• Every turtle can have its own shape. The ones available “out of the box” are `arrow`, `blank`, `circle`, `classic`, `square`, `triangle`, `turtle`.

```...
alex.shape("turtle")
...
```
• You can speed up or slow down the turtle’s animation speed. (Animation controls how quickly the turtle turns and moves forward). Speed settings can be set between 1 (slowest) to 10 (fastest). But if you set the speed to 0, it has a special meaning — turn off animation and go as fast as possible.

```alex.speed(10)
```
• A turtle can “stamp” its footprint onto the canvas, and this will remain after the turtle has moved somewhere else. Stamping works even when the pen is up.

Let’s do an example that shows off some of these new features. Note that the code below uses a for loop to make the turtle move repeatedly 30 times. We’ll cover for loops in the next chapter.

One more thing to be careful about. All except one of the shapes you see on the screen here are footprints created by `stamp`. After the loop, we change tess to be red, and that way you see where the actual turtle is (the red one is not a stamp - it’s tess!).

Mixed up program

The following program uses the stamp method to create a circle of turtle shapes as shown to the left:

But the lines are mixed up. The program should do all necessary set-up, create the turtle, set the shape to “turtle”, and pick up the pen. Then the turtle should repeat the following ten times: go forward 50 pixels, leave a copy of the turtle at the current position, reverse for 50 pixels, and then turn right 36 degrees. After the loop, set the window to close when the user clicks in it.

Drag the blocks of statements from the left column to the right column and put them in the right order with the correct indention. Click on Check Me to see if you are right. You will be told if any of the lines are in the wrong order or are incorrectly indented.

Mixed up program

The following program uses the stamp method to create a line of turtle shapes as shown to the left:

But the lines are mixed up. The program should do all necessary set-up, create the turtle, set the shape to “turtle”, and pick up the pen. Then the turtle should repeat the following three times: go forward 50 pixels and leave a copy of the turtle at the current position. After the loop, set the window to close when the user clicks in it.

Drag the blocks of statements from the left column to the right column and put them in the right order with the correct indention. Click on Check Me to see if you are right. You will be told if any of the lines are in the wrong order or are incorrectly indented.