🐢 Python Turtle Graphics — Comprehensive Guide¶

The turtle module in Python is a built-in library that makes it easy to introduce programming to beginners. You control a “turtle” that moves and draws on the screen. It is perfect for learning loops, functions, geometry, and logic through visual feedback. Turtle methods are available using Python 2.6 and are fully supported in Python 3.x, including versions 3.10+, 3.11, and 3.12.

🔹 Getting Started

import turtle

t = turtle.Turtle()  # Create a turtle object
turtle.done()        # Keep the window open at the end

🧠 What Is the “Turtle”?

The turtle is a cursor (triangle by default) that moves around the screen.

It can go forward or backward
Turn right or left
Draw lines as it moves
Change shape, color, and size

You control the turtle with methods.

🔑 Common Mistake: self.forward(100) ❌

That only works inside a class. For Turtle, you must use:

t = turtle.Turtle()
t.forward(100)  # ✅

🔧 Core Turtle Methods by Category¶

🧭 Turtle Motion & Positioning

Method	Description
`forward(distance)` or `fd()`	Move forward
`backward(distance)` or `bk()`	Move backward
`right(angle)` or `rt()`	Turn right (clockwise)
`left(angle)` or `lt()`	Turn left (counterclockwise)
`goto(x, y)` or `setpos()`	Move to absolute position
`setx(x)` / `sety(y)`	Set x or y coordinate
`setheading(angle)` or `seth()`	Face a specific direction in degrees
`home()`	Go to (0, 0) and face right
`circle(radius, extent, steps)`	Draw a circle or arc
`dot(size, color)`	Draw a dot
`stamp()`	Stamp turtle shape at current location
`clearstamp(stampid)`	Remove a specific stamp
`clearstamps(n)`	Clear all or last `n` stamps
`undo()`	Undo last action
`speed(0-10)`	Set turtle animation speed

🧠 Turtle State & Status

Method	Description
`position()` or `pos()`	Current (x, y) position
`xcor()` / `ycor()`	Get x or y coordinate
`heading()`	Get current angle turtle is facing
`towards(x, y)`	Angle from current position to (x, y)
`distance(x, y)`	Distance to point
`isdown()`	Whether pen is down (drawing)
`isvisible()`	Whether the turtle is visible

✍️ Pen Control (Drawing Tools)

Method	Description
`penup()` or `pu()`	Lift the pen (stop drawing)
`pendown()` or `pd()`	Lower the pen (start drawing)
`pensize(width)` / `width()`	Set pen thickness
`pencolor(color)`	Set pen (line) color
`fillcolor(color)`	Set fill color
`begin_fill()` / `end_fill()`	Fill shape drawn between these calls
`color(pen, fill)`	Set pen and fill color together
`clear()`	Clear drawing but keep turtle position
`reset()`	Clear everything and reset turtle state
`write(text, move=False, align=...)`	Write text on screen

🐢 Turtle Appearance

Method	Description
`shape(name)`	Set turtle shape (e.g., `'turtle'`, `'circle'`)
`shapesize(wid, len, outline)`	Stretch turtle’s size
`shearfactor(factor)`	Tilt shape diagonally
`tilt(angle)`	Tilt shape clockwise
`showturtle()` or `st()`	Make turtle visible
`hideturtle()` or `ht()`	Hide the turtle
`resizemode('auto'/'user')`	Control size behavior
`get_shapepoly()`	Get shape as polygon points

🖼️ Screen Control & Events

Method	Description
`Screen()`	Get turtle window control object
`bgcolor(color)`	Set background color
`bgpic(filename)`	Set background image
`title("Window Title")`	Set window title
`onclick(func)` / `onkey(func, key)`	Bind click or key event
`listen()`	Focus screen to capture keys
`mainloop()` or `done()`	Start main loop (keep window open)
`tracer(n, delay)` / `update()`	Control animation redraw speed
`bye()`	Close turtle window

🧩 Miscellaneous / Advanced

Method	Description
`begin_poly()`	Start recording points for a shape
`end_poly()` / `get_poly()`	Stop and return polygon
`getcanvas()`	Access underlying Tkinter canvas
`getscreen()`	Get screen object (same as `Screen()`)
`delay(ms)`	Set animation delay in milliseconds
`window_width()` / `window_height()`	Get window size

🟢 Example: Draw a Filled Star

import turtle

t = turtle.Turtle()
t.color("gold")
t.begin_fill()

for _ in range(5):
    t.forward(100)
    t.right(144)

t.end_fill()
turtle.done()

🛑 Common Pitfalls and Fixes

Mistake	Fix
Forgetting `turtle.done()`	Window closes immediately after drawing
Using `turtle.forward()` without an object	Use `t = turtle.Turtle()` first
Mixing up `left()` and `right()`	Practice turning to understand directions
Drawing before `pendown()` or `penup()`	Know when the turtle is supposed to draw
Expecting `char` type in Python	Use strings of length 1 (e.g., `"A"`)