How to change size of turtle?

Question

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

This is what I have so far:

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()

Answer 1

Change this line:

tess.turtlesize(increase)

to instead be:

tess.turtlesize(*increase)

turtlesize() wants three separate values but you were passing one tuple of three values so we need to spread that tuple across the argument list.