eventemitter/emitter.py
def once(self, event, listener):
        """Add a listener that is only called once."""
        self.emit('new_listener', event, listener)
        self._once[event].append(listener)
        self._check_limit(event)
        return self
def once(self, event, listener):
        """Add a listener that is only called once."""
        self.emit('new_listener', event, listener)
        self._once[event].append(listener)
        self._check_limit(event)
        return self
def once ( self , event , listener ) : self . emit ( 'new_listener' , event , listener ) self . _once [ event ] . append ( listener ) self . _check_limit ( event ) return self
Add a listener that is only called once.
Add a listener that is only called once .