How to put geometry in a Toplevel in Tkinter?
Toplevels do not have a create_line method, though tk.Canvass do. So pack a Canvas in the Toplevel and then draw on the Canvas:
import Tkinter as tkroot = tk.Tk()top = tk.Toplevel(root, width = 300, height = 300)canvas = tk.Canvas(top, bg='white')canvas.pack(expand=tk.YES, fill=tk.BOTH)top.title("Population")canvas.create_line(10, 300-10, 10, 300)canvas.create_line(10, 300-10, 300-10, 10)root.mainloop()