import tkinter

class Application(tkinter.Frame):
    def __init__(self, master):
        tkinter.Frame.__init__(self, master)
        self.grid()
        self.create_widgets()

    def create_widgets(self):
        self.canvas = tkinter.Canvas(root, width=200, height=100)
        self.canvas.grid()
        self.canvas.bind('<B1-Motion>', self.draw)

    def draw(self, event):
        self.canvas.create_oval(event.x-1, event.y-1, event.x+1, event.y+1)

if __name__ == "__main__":
    root = tkinter.Tk()
    root.title("Hello, SQL.ru")
    app = Application(root)
    root.mainloop()

self.canvas = tkinter.Canvas(self, width=200, height=100)