class_docstr: Simple event to which event handlers can be attached. For instance::
  
      class Cls:
          def __init__(self):
              # Define event. The first parameter is the sender.
              self.event = Event(self)
  
      obj = Cls()
  
      def handler(sender):
          pass
  
      # Add event handler by using the += operator.
      obj.event += handler
  
      # Fire event.
      obj.event()
class_docstr_tok: ["Simple","event","to","which","event","handlers","can","be","attached",".","For","instance",":",":","class","Cls",":","def","__init__","(","self",")",":","#","Define","event",".","The","first","parameter","is","the","sender",".","self.event","=","Event","(","self",")","obj","=","Cls","(",")","def","handler","(","sender",")",":","pass","#","Add","event","handler","by","using","the","+=","operator",".","obj.event","+=","handler","#","Fire","event",".","obj.event","(",")"]
docstr: Remove a handler from this callback.
docstr_tok: ["Remove","a","handler","from","this","callback","."]
code: def __isub__(self, handler):
      """
      Remove a handler from this callback.
      """
      self._handlers.remove(handler)
      return self
  
imports: from __future__ import unicode_literals
  import inspect
  import os
  import signal
  import sys
  import threading
  import weakref
  from wcwidth import wcwidth
  from six.moves import range
label_desc: Use image node_id 5 for calling the Event obj's underlying member method code with example usage: obj.__isub__(handler) and returns: self