import turtle turtle.tracer(10, 0) # Increase the first argument to speed up the drawing. turtle.setworldcoordinates(0, 0, 700, 700) turtle.hideturtle() turtle.pensize(2) def drawKochCurve(startPosition, heading, length): if length < 1: # BASE CASE return else: # RECURSIVE CASE # Move to the start position. recursiveArgs = [] turtle.penup() turtle.goto(startPosition) turtle.setheading(heading) recursiveArgs.append({'position':turtle.position(), 'heading':turtle.heading()}) # Erase the middle third. turtle.forward(length / 3) turtle.pencolor('white') turtle.pendown() turtle.forward(length / 3) # Draw the bump. turtle.backward(length / 3) turtle.left(60) recursiveArgs.append({'position':turtle.position(), 'heading':turtle.heading()}) turtle.pencolor('black') turtle.forward(length / 3) turtle.right(120) recursiveArgs.append({'position':turtle.position(), 'heading':turtle.heading()}) turtle.forward(length / 3) turtle.left(60) recursiveArgs.append({'position':turtle.position(), 'heading':turtle.heading()}) for i in range(4): drawKochCurve(recursiveArgs[i]['position'], recursiveArgs[i]['heading'], length / 3) return def drawKochSnowflake(startPosition, heading, length): # A Koch snowflake is three Koch curves in a triangle. # Move to the starting position turtle.penup() turtle.goto(startPosition) turtle.setheading(heading) for i in range(3): # Record the starting position and heading. curveStartingPosition = turtle.position() curveStartingHeading = turtle.heading() drawKochCurve(curveStartingPosition, curveStartingHeading, length) # Move back to the start position for this side. turtle.penup() turtle.goto(curveStartingPosition) turtle.setheading(curveStartingHeading) # Move to the start position of the next side. turtle.forward(length) turtle.right(120) drawKochSnowflake((100, 500), 0, 500) turtle.exitonclick()