Paint.py

from Tkinter import *

class Paint(Frame):

    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.parent = parent
        self.color = "black"
        self.brush_size = 2
        self.setUI()

    def set_color(self, new_color):
        self.color = new_color

    def set_brush_size(self, new_size):
        self.brush_size = new_size

    def draw(self, event):
        self.canv.create_oval(event.x - self.brush_size,
                              event.y - self.brush_size,
                              event.x + self.brush_size,
                              event.y + self.brush_size,
                              fill=self.color, outline=self.color)

    def drawCircle(self,newX,newY,newColor,newBrushSize):
        self.canv.create_oval(newX-newBrushSize,
                              newY-newBrushSize,
                              newX + newBrushSize,
                              newY + newBrushSize,
                              fill=newColor, outline=newColor)

    def setUI(self):

        self.parent.title("MyTrajectoryPaint")
        self.pack(fill=BOTH, expand=1)

        self.columnconfigure(6, weight=1)
        self.rowconfigure(2, weight=1)

        self.canv = Canvas(self, bg="white")

        self.canv.grid(row=2, column=0, columnspan=7,
                       padx=5, pady=5, sticky=E+W+S+N)
        self.canv.bind("<B1-Motion>", self.draw)

        color_lab = Label(self, text="Color: ")
        color_lab.grid(row=0, column=0, padx=6)
	def setNewUI(self):
            red_btn = Button(self, text="Red", width=10,
                         command=lambda: self.set_color("red"))
            red_btn.grid(row=0, column=1)


            green_btn = Button(self, text="Green", width=10,
                           command=lambda: self.set_color("green"))
            green_btn.grid(row=0, column=2)

            blue_btn = Button(self, text="Blue", width=10,
                          command=lambda: self.set_color("blue"))
            blue_btn.grid(row=0, column=3)

            black_btn = Button(self, text="Black", width=10,
                           command=lambda: self.set_color("black"))
            black_btn.grid(row=0, column=4)

            white_btn = Button(self, text="White", width=10,
                           command=lambda: self.set_color("white"))
            white_btn.grid(row=0, column=5)

            clear_btn = Button(self, text="Clear all", width=10,
                           command=lambda: self.canv.delete("all"))
            clear_btn.grid(row=0, column=6, sticky=W)

            size_lab = Label(self, text="Brush size: ")
            size_lab.grid(row=1, column=0, padx=5)
            one_btn = Button(self, text="Two", width=10,
                         command=lambda: self.set_brush_size(2))
            one_btn.grid(row=1, column=1)

            two_btn = Button(self, text="Five", width=10,
                         command=lambda: self.set_brush_size(5))
            two_btn.grid(row=1, column=2)

            five_btn = Button(self, text="Seven", width=10,
                          command=lambda: self.set_brush_size(7))
            five_btn.grid(row=1, column=3)

            seven_btn = Button(self, text="Ten", width=10,
                           command=lambda: self.set_brush_size(10))
            seven_btn.grid(row=1, column=4)

            ten_btn = Button(self, text="Twenty", width=10,
                         command=lambda: self.set_brush_size(20))
            ten_btn.grid(row=1, column=5)

            twenty_btn = Button(self, text="Fifty", width=10,
                            command=lambda: self.set_brush_size(50))
            twenty_btn.grid(row=1, column=6, sticky=W)


def main():
    root = Tk()
    root.geometry("850x500+100+100")
    app = Paint(root)
    root.mainloop()

if __name__ == '__main__':
    main()
#main()