code: def disconnect(receiver, signal=Any, sender=Any, weak=True):
      
      if signal is None:
          raise errors.DispatcherTypeError(
              'Signal cannot be None (receiver=%r sender=%r)'%( receiver,sender)
          )
      if weak: receiver = saferef.safeRef(receiver)
      senderkey = id(sender)
      try:
          signals = connections[senderkey]
          receivers = signals[signal]
      except KeyError:
          raise errors.DispatcherKeyError(
              """No receivers found for signal %r from sender %r""" %(
                  signal,
                  sender
              )
          )
      try:
          # also removes from receivers
          _removeOldBackRefs(senderkey, signal, receiver, receivers)
      except ValueError:
          raise errors.DispatcherKeyError(
              """No connection to receiver %s for signal %s from sender %s""" %(
                  receiver,
                  signal,
                  sender
              )
          )
      _cleanupConnections(senderkey, signal)
docs: Disconnect receiver from sender for signal
  
      receiver -- the registered receiver to disconnect
      signal -- the registered signal to disconnect
      sender -- the registered sender to disconnect
      weak -- the weakref state to disconnect
  
      disconnect reverses the process of connect,
      the semantics for the individual elements are
      logically equivalent to a tuple of
      (receiver, signal, sender, weak) used as a key
      to be deleted from the internal routing tables.
      (The actual process is slightly more complex
      but the semantics are basically the same).
  
      Note:
          Using disconnect is not required to cleanup
          routing when an object is deleted, the framework
          will remove routes for deleted objects
          automatically.  It's only necessary to disconnect
          if you want to stop routing to a live object.
          
      returns None, may raise DispatcherTypeError or
          DispatcherKeyError