code: def decipher(self,string):
                   
          string = self.remove_punctuation(string,filter='[^'+self.chars+']')
          ret = ''
          for i in range(0,len(string),3):
              ind = tuple([int(string[i+k]) for k in [0,1,2]])
              ret += IND2L[ind]
          return ret
docs: Decipher string using Delastelle cipher according to initialised key.
  
          Example::
  
              plaintext = Delastelle('APCZ WRLFBDKOTYUQGENHXMIVS').decipher(ciphertext)     
  
          :param string: The string to decipher.
          :returns: The deciphered string. The plaintext will be 1/3 the length of the ciphertext.