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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def encipher(self,string):
 """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. """
                
        string = self.remove_punctuation(string)
        step1 = self.pb.encipher(string)
        evens = step1[::2]
        odds = step1[1::2]
        step2 = []
        for i in range(0,len(string),self.period):
            step2 += evens[i:int(i+self.period)]
            step2 += odds[i:int(i+self.period)]
        return self.pb.decipher(''.join(step2))