Python Turtle - First Turtles & Coordinate System

This is full working source code for turtle t and z. Run this source and than we will explain:

import turtle

t = turtle.Turtle()
t.color("red")

t.begin_fill()
t.goto( 300,  300)
t.goto(-300,  300)
t.goto(-300, -300)
t.goto( 300, -300)
t.goto( 300,  300)
t.end_fill()

t.hideturtle()

z = turtle.Turtle()
z.color("yellow")

z.begin_fill()
z.goto( 200,  200)
z.goto(-200,  200)
z.goto(-200, -200)
z.goto( 200, -200)
z.goto( 200,  200)
z.end_fill()

z.hideturtle()

Creating new turtle is extremely easy, but of course, first we must import turtle module to have access to all methods.

In this simple example we will create 2 turtles, t and z. You can experiment with only one turtle t, if it's easier for you, like this:

import turtle

t = turtle.Turtle()

Then we will set color to be red using color() method:

t.color("red")

We must fill shape with that color when turtle object is done with movement. To do that begin_fill() method is used:

t.begin_fill()

In this tutorial it's all about coordinate system. Numbers you see passed to goto() functions are x and y. A turtle must travel to reach those coordinates from center of coordinate system, which is x = 0 and y = 0.

By telling t.goto(300, 300) turtle will reach upper right position and stop there waiting for next goto() command:

t.goto( 300,  300)

You can experiment a little bit, but to create red box we see in a picture, these steps are needed:

t.goto(-300,  300)
t.goto(-300, -300)
t.goto( 300, -300)
t.goto( 300,  300)

After we are done with movement, it's time to use end_fill() method, that will "finish" painting:

t.end_fill()

And if there's need to hide turtle object t, we can use hideturtle() method:

t.hideturtle()

To create z turtle (object) we will use these lines:

z = turtle.Turtle()
z.color("yellow")

z.begin_fill()
z.goto( 200,  200)
z.goto(-200,  200)
z.goto(-200, -200)
z.goto( 200, -200)
z.goto( 200,  200)
z.end_fill()

z.hideturtle()

Yellow shape created with z movement is, of course, smaller because coordinates are smaller too.

Please note, important thing here is that we are dealing with turtle coordinates, and not with angles and paths where a turtle must be pushed. 

That will be a topic for next tutorial.