How to change size of turtle?
<p>I am trying to double the size of the turtle in the window every time I press <code>x</code> on my keyboard. I tried using <code>.turtlesize(2,2,2)</code>, but that's not right. I need to double every time the key is pressed so if the turtle size is <code>(1,1,1)</code>, it will become <code>(2,2,2)</code> then <code>(4,4,4)</code> and so on each time I press <code>x</code>. </p>

<p>This is what I have so far:</p>

<pre><code>import turtle
turtle.setup(500,500)
wn = turtle.Screen()
wn.title("Commands")
wn.bgcolor("black")

tess = turtle.Turtle()
tess.shape("triangle")
tess.color("red")
tess.left(90)

def increaseSize():
    size = tess.turtlesize()
    increase = tuple([2 * num for num in size])
    tess.turtlesize(increase) #this is where the error occurs

wn.onkey(increaseSize, "x")
wn.listen()
</code></pre>