yaml_listener.py 文件源码

def _GenerateEventParameters(self,
                               stream,
                               loader_class=yaml.loader.SafeLoader):
    """Creates a generator that yields event, loader parameter pairs.

    For use as parameters to HandleEvent method for use by Parse method.
    During testing, _GenerateEventParameters is simulated by allowing
    the harness to pass in a list of pairs as the parameter.

    A list of (event, loader) pairs must be passed to _HandleEvents otherwise
    it is not possible to pass the loader instance to the handler.

    Also responsible for instantiating the loader from the Loader
    parameter.

    Args:
      stream: String document or open file object to process as per the
        yaml.parse method.  Any object that implements a 'read()' method which
        returns a string document will work.
      Loader: Loader class to use as per the yaml.parse method.  Used to
        instantiate new yaml.loader instance.

    Yields:
      Tuple(event, loader) where:
        event: Event emitted by PyYAML loader.
        loader_class: Used for dependency injection.
    """
    assert loader_class is not None
    try:
      loader = loader_class(stream)
      while loader.check_event():
        yield (loader.get_event(), loader)
    except yaml.error.YAMLError, e:
      raise yaml_errors.EventListenerYAMLError(e)