Robot Turtle with Python

Turtle Graphics programs are a cool part of computing history, and a useful way to teach programming.

One of the simpler ways to try out Turtle programming, today, is through the Python Turtle Module.

Tip: Be sure that Python is installed with the Tkinter module option enabled. This is usually a checkbox during install on Windows. On Linux and Mac it may be a specially named package, such as python3-tk.

sudo apt install python3-tk

Type the command python into a terminal. Then, in the interactive Python session, type:

from turtle import *

Now, to list the available commands, type:

dir()

To learn more about a particular command, type use the help function:

help(forward)

Tip: Press Q to exit the help viewer and return to Python.

To display the Turtle window, type your first command:

forward(100)

Tip: A new separate window should appear with an arrow pointing to the right.

The tip of the arrow is your turle. The line coming out of the arrow is the 100 pixels of travel the turtle just completed.

Now a list of interesting commands to explore.

Move the turtle:

• forward(100) move the turtle forward 100 pixels
• right(45) / left(90) rotate left or right the number of degrees specified
• xcor() / ycor() - show the current x or y coordinate
• heading() - get the current heading (in degrees)
• goto(0,0) - go directly to the x and y cordinates given

Tip: All commands whould end in () - and some take arguments - a number or string of text between the ().

Control the drawn line:

• penup() - lift the pen to allow moving without drawing
• pendown() - lower the pen to resume drawing
• pensize(10) - change the pen line thickness to the given number of pixels
• color('green') - change the turtle (and ink) to the given color

Text output:

• `write('hello world') - write the given text next to the turtle
• setx(100) / sety(100) - jump to the given x / y coordinate

Stamps:

• shape("circle") - change the turle's shape
• stamp() - "stamp" the turtle's current appearance into the canvas

Clean up:

• hideturtle() - hide the turtle
• showturtle() - show the turtle
• clearscreen() - empty the canvas of all drawings
• undo() - undo the previous command