Python Turtle Graphics: Commands, Examples, and Code Snippets

The turtle library is a standard Python module for simple graphics; after import turtle you can control a virtual turtle that moves on a canvas, leaving a trail that forms the drawn image.

Drawing principle: the turtle starts at the center of the window; its movements (forward, backward, turns, etc.) create visible lines, and its appearance can be customized (color, pen width, fill).

Window setup command

turtle.setup(400, 300, 200, 100) – sets width, height, and the distance from the left and top edges of the screen; the origin is at the top‑left corner, units are pixels.

Movement commands

turtle.goto(x, y) – jumps directly to coordinates (x, y) with the window center as origin.

turtle.fd(d) or turtle.forward(d) – moves forward d pixels in the current heading.

turtle.bk(d) or turtle.backward(d) – moves backward d pixels.

turtle.circle(r, angle) – draws an arc of angle degrees with radius r .

Direction commands

turtle.seth(angle) – sets the heading to angle degrees (0° points to the right, positive is counter‑clockwise).

turtle.left(angle) – rotates left by angle degrees.

turtle.right(angle) – rotates right by angle degrees.

Pen control commands

turtle.penup() – lifts the pen (no drawing).

turtle.pendown() – puts the pen down (drawing).

turtle.pensize(width) – sets pen thickness.

turtle.pencolor(color) – sets pen color (name, RGB tuple, or hex code).

turtle.fillcolor(color) – sets fill color for shapes.

turtle.begin_fill() / turtle.end_fill() – starts and ends a fill region.

turtle.filling() – returns whether a fill is in progress.

Examples

1. Equilateral triangle (side 200 px):

<code>import turtle as t</code>
<code>for i in range(3):</code>
<code>    t.seth(i*120)</code>
<code>    t.fd(200)</code>

2. Square (side 200 px):

<code>import turtle</code>
<code>d = 0</code>
<code>for i in range(4):</code>
<code>    turtle.fd(200)</code>
<code>    d = d + 90</code>
<code>    turtle.seth(d)</code>

3. Rhombus (side 200 px):

<code>import turtle as t</code>
<code>t.right(-30)</code>
<code>for i in range(2):</code>
<code>    t.fd(200)</code>
<code>    t.right(60*(i+1))</code>
<code>for i in range(2):</code>
<code>    t.fd(200)</code>
<code>    t.right(60*(i+1))</code>

4. Hexagon (side 200 px):

<code>import turtle as t</code>
<code>for i in range(6):</code>
<code>    t.fd(200)</code>
<code>    t.left(60)</code>

5. Pentagon (side 200 px):

<code>import turtle</code>
<code>d = 0</code>
<code>for i in range(5):</code>
<code>    turtle.fd(200)</code>
<code>    d += 72</code>
<code>    turtle.seth(d)</code>

6. Four‑petal flower (radius 200 px, 90° arcs):

<code>import turtle as t</code>
<code>for i in range(4):</code>
<code>    t.seth(90*(i+1))</code>
<code>    t.circle(200,90)</code>
<code>    t.seth(-90 + i*90)</code>
<code>    t.circle(200,90)</code>

7. Four‑leaf clover:

<code>import turtle</code>
<code>for i in range(4):</code>
<code>    turtle.right(90)</code>
<code>    turtle.circle(50,180)</code>

8. Star (radius 90 px):

<code>import turtle</code>
<code>for i in range(4):</code>
<code>    turtle.circle(-90,90)</code>
<code>    turtle.right(180)</code>

9. Concentric circles (starting radius 10 px, step 40 px):

<code>import turtle</code>
<code>r = 10</code>
<code>head = 90</code>
<code>for i in range(4):</code>
<code>    turtle.seth(head)</code>
<code>    turtle.circle(r)</code>
<code>    r = r + 40</code>
<code>turtle.done()</code>

10. Another concentric‑circle pattern with pen up/down handling:

<code>import turtle</code>
<code>r = 10</code>
<code>dr = 40</code>
<code>head = 90</code>
<code>for i in range(4):</code>
<code>    turtle.pendown()</code>
<code>    turtle.circle(r)</code>
<code>    r += dr</code>
<code>    turtle.penup()</code>
<code>    turtle.seth(-head)</code>
<code>    turtle.fd(dr)</code>
<code>    turtle.seth(0)</code>
<code>turtle.done()</code>

The examples demonstrate that using the turtle library is straightforward, and with Python's simplicity these graphics can be created quickly after a brief introductory tutorial.