def encipher(self,string):
string = self.remove_punctuation(string)<EOL>step1 = self.pb.encipher(string)<EOL>evens = step1[::<NUM_LIT:2>]<EOL>odds = step1[<NUM_LIT:1>::<NUM_LIT:2>]<EOL>step2 = []<EOL>for i in range(<NUM_LIT:0>,len(string),self.period):<EOL><INDENT>step2 += evens[i:int(i+self.period)]<EOL>step2 += odds[i:int(i+self.period)]<EOL><DEDENT>return self.pb.decipher('<STR_LIT>'.join(step2))<EOL>
Encipher string using Bifid cipher according to initialised key. Punctuation and whitespace
        are removed from the input.       

        Example::

            ciphertext = Bifid('phqgmeaylnofdxkrcvszwbuti',5).encipher(plaintext)     

        :param string: The string to encipher.
        :returns: The enciphered string.