Turtle Star

By Monty, 18th April 2015

TurtleStarA very simple Turtle program. Turtle can draw intricate shapes using programs that repeat simple moves.

Turtle graphics is a popular way for introducing programming to kids. It was part of the original Logo programming language developed by Wally Feurzig and Seymour Papert in 1966.

Imagine a robotic turtle starting at (0, 0) in the x-y plane. After an import turtle, give it the command turtle.forward(15), and it moves (on-screen!) 15 pixels in the direction it is facing, drawing a line as it moves. Give it the command turtle.right(25), and it rotates in-place 25 degrees clockwise.

  • color() sets pencolor and fillcolor.
  • speed() sets the turtle’s speed to an integer value in the range 0..10
  • setpos() moves turtle to an absolute position. If the pen is down, draw line.
  • begin_fill() is called just before drawing a shape to be filled.
  • forward() moves the turtle forward by the specified distance, in the direction the turtle is headed.
  • left() turns turtle left by angle units.
  • end_fill() fills the shape drawn after the last call to begin_fill().
#   Turtle Star
#   Adapted from https://docs.python.org/3/library/turtle.html
#   Turtle can draw intricate shapes using programs that repeat simple moves.

from turtle import *
size=790
color('green', 'blue')
speed('fastest')
setpos(-size/2,-32)
start=pos()             # Note starting position
begin_fill()
while True:
    forward(size)
    left (170)
    if abs(pos()-start) < 1:    # have we come back to start?
        break
end_fill()
done()

Further Information

Wikipedia:

In computer graphics, turtle graphics are vector graphics using a relative cursor (the "turtle") upon a Cartesian plane. Turtle graphics is a key feature of the Logo programming language.

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