yaml_listener.py 文件源码

def __init__(self, event_handler):
    """Initialize PyYAML event listener.

    Constructs internal mapping directly from event type to method on actual
    handler.  This prevents reflection being used during actual parse time.

    Args:
      event_handler: Event handler that will receive mapped events. Must
        implement at least one appropriate handler method named from
        the values of the _EVENT_METHOD_MAP.

    Raises:
      ListenerConfigurationError if event_handler is not an EventHandler.
    """
    if not isinstance(event_handler, EventHandler):
      raise yaml_errors.ListenerConfigurationError(
        'Must provide event handler of type yaml_listener.EventHandler')
    self._event_method_map = {}

    for event, method in _EVENT_METHOD_MAP.iteritems():

      self._event_method_map[event] = getattr(event_handler, method)