code: def get_events_with_n_cluster(event_number, condition='n_cluster==1'):
      '''Selects the events with a certain number of cluster.
  
      Parameters
      ----------
      event_number : numpy.array
  
      Returns
      -------
      numpy.array
      '''
  
      logging.debug("Calculate events with clusters where " + condition)
      n_cluster_in_events = analysis_utils.get_n_cluster_in_events(event_number)
      n_cluster = n_cluster_in_events[:, 1]
  #    return np.take(n_cluster_in_events, ne.evaluate(condition), axis=0)  # does not return 1d, bug?
      return n_cluster_in_events[ne.evaluate(condition), 0f get_events_with_n_cluster(event_number, condition='n_cluster==1'):
      '''Selects the events with a certain number of cluster.
  
      Parameters
      ----------
      event_number : numpy.array
  
      Returns
      -------
      numpy.array
      '''
  
      logging.debug("Calculate events with clusters where " + condition)
      n_cluster_in_events = analysis_utils.get_n_cluster_in_events(event_number)
      n_cluster = n_cluster_in_events[:, 1]
  #    return np.take(n_cluster_in_events, ne.evaluate(condition), axis=0)  # does not return 1d, bug?
      return n_cluster_in_events[ne.evaluate(condition), 0]
docs: Selects the events with a certain number of cluster.
  
      Parameters
      ----------
      event_number : numpy.array
  
      Returns
      -------
      numpy.array