code: def decipher(self,string):
          '''Decipher string using Columnar Transposition cipher according to initialised key. Punctuation and whitespace
          are removed from the input.
  
          Example::
  
              plaintext = ColTrans('GERMAN').decipher(ciphertext)     
  
          :param string: The string to decipher.
          :returns: The deciphered string.
          '''           
          string = self.remove_punctuation(string)        
          ret = ['_']*len(string)
          L,M = len(string),len(self.keyword)
          ind = self.unsortind(self.keyword)
          upto = 0
          for i in range(len(self.keyword)):
              thiscollen = (int)(L/M)
              if ind[i]< L%M: thiscollen += 1
              ret[ind[i]::M] = string[upto:upto+thiscollen]
              upto += thiscollen
          return ''.join(retf decipher(self,string):
          '''Decipher string using Columnar Transposition cipher according to initialised key. Punctuation and whitespace
          are removed from the input.
  
          Example::
  
              plaintext = ColTrans('GERMAN').decipher(ciphertext)     
  
          :param string: The string to decipher.
          :returns: The deciphered string.
          '''           
          string = self.remove_punctuation(string)        
          ret = ['_']*len(string)
          L,M = len(string),len(self.keyword)
          ind = self.unsortind(self.keyword)
          upto = 0
          for i in range(len(self.keyword)):
              thiscollen = (int)(L/M)
              if ind[i]< L%M: thiscollen += 1
              ret[ind[i]::M] = string[upto:upto+thiscollen]
              upto += thiscollen
          return ''.join(ret)
docs: Decipher string using Columnar Transposition cipher according to initialised key. Punctuation and whitespace
          are removed from the input.
  
          Example::
  
              plaintext = ColTrans('GERMAN').decipher(ciphertext)     
  
          :param string: The string to decipher.
          :returns: The deciphered string.