Python Turtle Graphics Basics Reference Guide

1. Introduction to Turtle Graphics

The Python turtle module allows you to create pictures and shapes by providing a virtual canvas. It's an excellent way to learn programming and create graphics. In Skulpt, you can use turtle graphics directly in the browser.

2. Setting Up the Turtle Environment

Before you start drawing, you need to import the turtle module and create a turtle object:

import turtle
t = turtle.Turtle()

3. Basic Movement Commands

The turtle can move forward, backward, and turn left or right.

Forward and Backward

t.forward(100)  # Moves the turtle forward by 100 units
t.backward(50)  # Moves the turtle backward by 50 units

Turning Left and Right

t.left(90)   # Turns the turtle left by 90 degrees
t.right(45)  # Turns the turtle right by 45 degrees

4. Pen Control

You can control the pen to change its color, size, or lift it up and down.

Changing Pen Color

t.pencolor("red")       # Sets the pen color to red

Changing Pen Size

t.pensize(5)  # Sets the pen thickness to 5 units

Pen Up and Pen Down

t.penup()   # Lifts the pen; turtle moves without drawing
t.pendown() # Puts the pen down; turtle draws when moving

5. Drawing Basic Shapes

Drawing a Square

for _ in range(4):
    t.forward(100)
    t.right(90)

Drawing a Circle

t.circle(50)  # Draws a circle with radius 50 units

6. Using Loops for Patterns

You can create complex patterns by combining loops with turtle commands.

Spiral Pattern Example

for i in range(36):
    t.forward(i * 5)
    t.right(144)

7. Setting the Screen

The screen can be customized by setting its background color or size.

screen = turtle.Screen()
screen.bgcolor("lightblue")  # Sets the background color

8. Functions in Turtle Graphics

You can define functions to reuse drawing code.

Example: Drawing a Star

def draw_star(size):
    for _ in range(5):
        t.forward(size)
        t.right(144)

draw_star(100)

9. Changing Turtle Speed

Adjust the speed at which the turtle moves.

t.speed(1)   # Slowest speed
t.speed(10)  # Fastest speed

10. Hiding and Showing the Turtle

You can hide the turtle icon to see only the drawing.

t.hideturtle()  # Hides the turtle icon
t.showturtle()   # Shows the turtle icon again