title: Retrieving matched record ids in the recordlinkage library
body: <p>I was trying out this example: <a href="https://recordlinkage.readthedocs.io/en/latest/notebooks/data_deduplication.html" rel="nofollow noreferrer">https://recordlinkage.readthedocs.io/en/latest/notebooks/data_deduplication.html</a></p>
  
  <p>Following is the code snippet:</p>
  
  <pre><code>import recordlinkage
  from recordlinkage.datasets import load_febrl1
  
  dfA = load_febrl1()
  
  # Indexation step
  indexer = recordlinkage.Index()
  indexer.block(left_on='given_name')
  candidate_links = indexer.index(dfA)
  
  compare_cl = recordlinkage.Compare()
  
  compare_cl.exact('given_name', 'given_name', label='given_name')
  compare_cl.string('surname', 'surname', method='jarowinkler', threshold=0.85, label='surname')
  compare_cl.exact('date_of_birth', 'date_of_birth', label='date_of_birth')
  compare_cl.exact('suburb', 'suburb', label='suburb')
  compare_cl.exact('state', 'state', label='state')
  compare_cl.string('address_1', 'address_1', threshold=0.85, 
  label='address_1')
  
  features = compare_cl.compute(candidate_links, dfA)
  matches = features[features.sum(axis=1) &gt; 3]
  print(len(matches))
  </code></pre>
  
  <p>I would now like to separately print the record_ids that have been matched.I tried listing down the column names of 'matches', but record_id isn't a part of it, and I cannot seem to figure out a way to get it done(I just want the record_ids separately)</p>
  
  <p>Is there a way to retrieve the record_ids, and maybe either print it separately or store it as a list or an array?</p>