code: def dist(src, tar, method=sim_levenshtein):
      
      if callable(method):
          return 1 - method(src, tar)
      else:
          raise AttributeError('Unknown distance function: ' + str(method))
docs: Return a distance between two strings.
  
      This is a generalized function for calling other distance functions.
  
      Parameters
      ----------
      src : str
          Source string for comparison
      tar : str
          Target string for comparison
      method : function
          Specifies the similarity metric (:py:func:`sim_levenshtein` by default)
          -- Note that this takes a similarity metric function, not a distance
          metric function.
  
      Returns
      -------
      float
          Distance according to the specified function
  
      Raises
      ------
      AttributeError
          Unknown distance function
  
      Examples
      --------
      >>> round(dist('cat', 'hat'), 12)
      0.333333333333
      >>> round(dist('Niall', 'Neil'), 12)
      0.6
      >>> dist('aluminum', 'Catalan')
      0.875
      >>> dist('ATCG', 'TAGC')
      0.75