turtle_examples.py

# just some sample code I made for demonstrating the turtle lib in Python

import turtle
import math
import random

turtle.colormode(255)


RGBCMY = [
    (255, 0, 0),
    (255, 255, 0),
    (0, 255, 0),
    (0, 255, 255),
    (0, 0, 255),
    (255, 0, 255)]

RAINBOW = [
    (255, 0, 0),
    (255, 128, 0),
    (255, 255, 0),
    (128, 255, 0),
    (0, 255, 0),
    (0, 255, 128),
    (0, 255, 255),
    (0, 128, 255),
    (0, 0, 255),
    (128, 0, 255),
    (255, 0, 255),
    (255, 0, 128)]


def fractal(length, depth):
    if depth == 0:
        turtle.forward(length)
    else:
        fractal(length / 3, depth - 1)
        turtle.right(60)
        fractal(length / 3, depth - 1)
        turtle.left(120)
        fractal(length / 3, depth - 1)
        turtle.right(60)
        fractal(length / 3, depth - 1)


def polygon(sides, size):
    angle = 360 / sides
    for i in range(sides):
        turtle.forward(size)
        turtle.left(angle)


def polygon2(sides, size):
    radius = size
    angle = 360 / sides
    length = 2 * radius * math.sin(math.radians(angle / 2))
    turtle.reset()
    turtle.penup()
    turtle.left(90)
    turtle.forward(radius)
    turtle.right(90 + (angle / 2))
    turtle.pendown()
    for i in range(sides):
        turtle.forward(length)
        turtle.right(angle)


def cool_pattern(colors):
    turtle.reset()
    turtle.colormode(255)
    for color in colors:
        turtle.pencolor(color)
        polygon(6, 100)
        turtle.right(360/len(colors))


def star(points=5, radius=100, direction=90, color=(0, 0, 0)):
    angle = 180-(360/points) if points % 2 == 0 else 180-(180/points)
    length = 2 * radius * math.sin(math.radians(angle/2))
    turtle.speed(10)
    turtle.penup()
    turtle.home()
    turtle.setheading(direction)
    turtle.forward(radius)
    turtle.right(90 + angle/2)
    turtle.pendown()
    turtle.pencolor(color)
    if points % 2 == 0 and (points//2) % 2 == 1:
        points = points // 2
        for i in range(points):
            turtle.forward(length)
            turtle.right(angle)
        turtle.penup()
        turtle.home()
        turtle.setheading(direction+180 if direction+180 < 360 else direction-180)
        turtle.forward(radius)
        turtle.right(90 + angle/2)
        turtle.pendown()
        for i in range(points):
            turtle.forward(length)
            turtle.right(angle)
    else:
        for i in range(points):
            turtle.forward(length)
            turtle.right(angle)


def rainbow_pattern(points, colors, radius=250):
    turtle.reset()
    for i, color in enumerate(colors):
        angle = 360 / points / len(colors)
        direction = 90 - (i * angle)
        star(points, color=color, direction=direction, radius=radius)