python - Tkinter mouse event initially triggered -

i'm learning tkinter , cannot find solution problem here nor outside stackoverflow. in nutshell, events bind widgets triggered initialy , don't respond actions.

in example, red rectangle appears on canvas when run code, ,

color=random.choice(['red', 'blue']) 

revealed event binding doesn't work after that:

import tkinter tk  class application(tk.frame):     def __init__(self, master=none):         tk.frame.__init__(self, master)         self.can = tk.canvas(master, width=200, height=200)         self.can.bind('<button-2>', self.draw())         self.can.grid()     def draw(self):         self.can.create_rectangle(50, 50, 100, 100, fill='red')  app = application() app.mainloop() 

i use mac platform, haven't got clue role in problem. please point me @ mistake did here?

there 2 things here:

1. you should not calling self.draw when bind <button-2>.

2. when click <button-2>, event object sent self.draw. thus, need make function accept argument, if not use it.

in all, script should (the lines changed in comment boxes):

import tkinter tk  class application(tk.frame):     def __init__(self, master=none):         tk.frame.__init__(self, master)         self.can = tk.canvas(master, width=200, height=200)         #######################################         self.can.bind('<button-2>', self.draw)         #######################################         self.can.grid()     #######################     def draw(self, event):     #######################         self.can.create_rectangle(50, 50, 100, 100, fill='red')  app = application() app.mainloop()