class_docstr: Mean reciprocal rank metric.
docstr: :class:`MeanReciprocalRankMetric`.
  
  :param threshold: The label threshold of relevance degree.
docstr_tok: [":","class",":","`","MeanReciprocalRankMetric","`",".",":","param","threshold",":","The","label","threshold","of","relevance","degree","."]
code: def __init__(self, threshold: float = 0.0):
      """
      :class:`MeanReciprocalRankMetric`.
  
      :param threshold: The label threshold of relevance degree.
      """
      self._threshold = threshold
  
imports: import numpy
  from matchzoo.engine.base_metric import BaseMetric, sort_and_couple
label_desc: Use image node_id 1 to create a new MeanReciprocalRank object from inherited base classes: BaseMetric with example: obj = MeanReciprocalRank(threshold)