import tkinter

def drawGrid(canvas, gridSize):
    pass

def runDrawGrid():
    root = tkinter.Tk()
    canvas = tkinter.Canvas(root, width=400, height=400)
    canvas.configure(bd=0, highlightthickness=0)
    canvas.pack()
    
    drawGrid(canvas, 4) # your call here!
    
    root.mainloop()

runDrawGrid()