code: def check_missing_files(client):
      
      missing = defaultdict(list)
  
      for path, dataset in client.datasets.items():
          for file in dataset.files:
              filepath = (path.parent / file)
              if not filepath.exists():
                  missing[str(
                      path.parent.relative_to(client.renku_datasets_path)
                  )].append(
                      os.path.normpath(str(filepath.relative_to(client.path)))
                  )
  
      if not missing:
          return True
  
      click.secho(
          WARNING + 'There are missing files in datasets.'
          # '\n  (use "renku dataset clean <name>" to clean them)'
      )
  
      for dataset, files in missing.items():
          click.secho(
              '\n\t' + click.style(dataset, fg='yellow') + ':\n\t  ' +
              '\n\t  '.join(click.style(path, fg='red') for path in files)
          )
  
      return False
docs: Find missing files listed in datasets.