I am creating a graphics program that draws 100 x 100 squares next to each other depending on the user-specified grid size. The user also inputs 4 colours for the squares to be coloured (e.g. if they enter red,green,blue,yellow the squares will be coloured in that order, repeating the colours).

Is it possible to loop the colours from the variables the user has given?

Here is what I have so far:

def main():
    print ("Please enter four comma seperated colours e.g.: 'red,green,blue,yellow'\n\
    Allowed colours are: red, green, blue, yellow and cyan")
    col1, col2, col3, col4 = input("Enter your four colours: ").split(',')
    win = GraphWin ("Squares", 500, 500)
    colours = [col1, col2, col3, col4]
    drawSquare (win, col1, col2, col3, col4, colours)
    win.getMouse()
    win.close()


def drawSquare(win, col1, col2, col3, col4, colours):
    for i in range (4):
        for j in range (len(colours)):
            colour = colours[j]
            x = 50 + (i * 50)
            circle = Circle (Point (x,50), 20)
            circle.setFill(colour)
            circle.draw(win)

I think I should be using a list in some way, but can't work out exactly how to do it. Can anybody help?