code: def encode(self, word, max_length=4, zero_pad=True):
          
          # In the most extreme case, 3 characters of NYSIIS input can be
          # compressed to one character of output, so give it triple the
          # max_length.
          return self._soundex.encode(
              self._nysiis.encode(word, max_length=max_length * 3),
              max_length,
              zero_pad=zero_pad,
          )
docs: Return the Oxford Name Compression Algorithm (ONCA) code for a word.
  
          Parameters
          ----------
          word : str
              The word to transform
          max_length : int
              The maximum length (default 5) of the code to return
          zero_pad : bool
              Pad the end of the return value with 0s to achieve a max_length
              string
  
          Returns
          -------
          str
              The ONCA code
  
          Examples
          --------
          >>> pe = ONCA()
          >>> pe.encode('Christopher')
          'C623'
          >>> pe.encode('Niall')
          'N400'
          >>> pe.encode('Smith')
          'S530'
          >>> pe.encode('Schmidt')
          'S530'