title: Problems in Python getting multiple selections from Tkinter listbox
body: <p>This is the same problem I posed earlier today and which a couple of you tried to help me with, but I can't get it to work. All I want to do is to populate "ichose" with the multiple selections I make when I click on the listbox.</p>
  
  <pre><code>import Tkinter as tk
  from Tkinter import *
  global ichose
  
  class App(tk.Frame):
      def __init__(self, master):
          tk.Frame.__init__(self,master)
          self.master=master
          self.grid()
          self.ichose = ()
  
          self.l = Listbox(self, height=10, selectmode=EXTENDED)
          # Selectmode can be SINGLE, BROWSE, MULTIPLE or EXTENDED. Default BROWSE
          self.l.grid(column=0, row=0, sticky=(N,W,E,S))
          self.l.bind("Double-Button-1", self.entered)
  
          s = Scrollbar(self, orient=VERTICAL, command=self.l.yview)
          s.grid(column=0, row=0, sticky=(N,S,E))
          self.l['yscrollcommand'] = s.set
  
          for i in range(1,101):
              self.l.insert('end', 'Line %d of 100' % i)
  
  
      def entered(self, event):
          self.ichose = self.selection_get()
          self.ichose = ('hello')
  
  root=tk.Tk()
  root.title('Listbox Problem')
  root.geometry('200x200')
  app=App(root)
  root.mainloop()
  
  print app.ichose
  </code></pre>
  
  <p>Whatever I do, "ichose" comes out as an empty tuple ().
  It's clear that the function "entered" is never called because I never see the test string 'hello'.</p>
  
  <p>I also don't know what the various options are as in "Double-Button-", "&lt;>" etc. Where can I find a list and explanation of each one?</p>
  
  <p>If somebody could please just modify my program so the "print ichose" works, I'd be really grateful. You can see from my program that I don't really know what I'm doing but am keen to learn. Thank you.</p>