Drawing with Python Turtle

A Code Walkthrough for Young Coders

Ages 9–12 • Reading code, not just running it • About 20 minutes

Python has a fun module called turtle. It gives you a tiny turtle that holds a pen. When you tell the turtle to walk, it drags the pen behind it and draws on the screen. This page walks through a real Python program that uses the turtle to draw hexagons and squares, and explains what every part of the code does.

1. What does the program draw?

When you run the program, the turtle starts in the middle of the screen and walks around drawing shapes. Here is the finished picture:

The turtle draws three sets of three hexagons, then two squares.

Look closely — you can see big hexagons stacked on top of each other (those are drawn three times, so they look extra dark), then medium and small hexagons branching off, and finally two squares. Every line was made by the turtle walking forward and turning.

2. The big idea: forward and turn

The turtle only knows two basic moves:

Walk forward some number of steps.
Turn left or right by some number of degrees.

That’s it! Every shape in the picture is just walk — turn — walk — turn — walk … over and over.

To draw any closed shape, you can use this rule:

Total turning to come back to the start = 360°. So if a shape has N equal sides, each turn is 360 ÷ N degrees.

Square → 4 sides → turn 360 ÷ 4 = 90° at each corner.
Hexagon → 6 sides → turn 360 ÷ 6 = 60° at each corner.
Triangle → 3 sides → turn 360 ÷ 3 = 120° at each corner.

3. Reading the code, line by line

Setting up the turtle

import turtle

t = turtle.Turtle()

import turtle tells Python: “I want to use the turtle module.” The next line creates a turtle and gives it a short nickname, t, so we don’t have to type the full word every time.

A function that draws a hexagon

def draw_hex(side_length):
    t.pendown()
    for _ in range(6):
        t.forward(side_length)
        t.right(60)
    t.penup()

A function is a recipe with a name. This recipe is called draw_hex, and it draws a hexagon. The word side_length is a parameter — a blank you fill in when you use the recipe. draw_hex(250) means “draw a hexagon with sides 250 steps long.”

Inside the recipe:

pendown() — put the pen down so we draw.
The for loop repeats 6 times (once per side):
- forward(side_length) draws one side.
- right(60) turns the corner.
penup() — lift the pen so the turtle can move without drawing.

A function that draws a square

def draw_square(side_length):
    t.pendown()
    for _ in range(4):
        t.forward(side_length)
        t.right(90)
    t.penup()

Same idea as the hexagon, but it loops 4 times and turns 90° at each corner. Notice how similar these two functions look — the only differences are the number of sides and the turning angle.

The main pattern

for _ in range(3):
    draw_hex(250)

    t.right(90)
    t.forward(60)

    draw_hex(100)

    t.right(90)
    t.forward(40)

    draw_hex(120)

This loop runs 3 times. Each time, the turtle:

Draws a big hexagon (sides of 250).
Turns and walks (without drawing) to a new spot.
Draws a small hexagon (sides of 100).
Turns and walks again.
Draws a medium hexagon (sides of 120).

That’s why you see 3 sets of 3 hexagons in the picture. (The big hexagons happen to land on top of each other!)

The squares at the end

t.forward(300)
t.right(60)

draw_square(270)

t.left(30)
t.forward(110)
t.right(80)

draw_square(135)

turtle.done()

After all the hexagons, the turtle moves to a new spot, draws a big square, moves again, and draws a smaller square. Finally, turtle.done() tells the program: “We’re finished — please keep the picture window open so we can look at our drawing.”

4. Try it yourself

Experiment 1 — Make the hexagons bigger. Change draw_hex(250) to draw_hex(400). What happens to the picture?

Experiment 2 — Draw a triangle. Write a new function called draw_triangle. How many sides? What angle should it turn at each corner? (Hint: 360 ÷ 3.)

Experiment 3 — Add color. Before you call draw_hex, try t.color("blue"). Try "red", "green", or "purple" too.

Experiment 4 — Make a star. Try a loop that goes forward and turns by 144° five times. (Yes, 144 — not 72! That’s how five-pointed stars work.)

5. Words to know

module: A bundle of pre-made code that other programs can use. turtle is one of Python’s built-in modules.
function: A named recipe of instructions you can run as many times as you like. draw_hex is a function.
parameter: A blank you fill in when you call a function. side_length is a parameter.
loop: A way to tell the computer “do this N times.” for _ in range(6): repeats 6 times.
degree: A unit for measuring how much you turn. A full circle is 360 degrees; a square corner is 90 degrees.
pen up / pen down: Whether the turtle is drawing as it walks. Pen up = no line, pen down = line.

Download draw_shapes.py

To run it, save the file and type python3 draw_shapes.py in a terminal. (Make sure Python 3 is installed.)

Tip: don’t name your file turtle.py — Python already has a built-in module with that name, and it will get confused and try to import your file instead of its own.