def set_seq2(self, b):
if b is self.b:<EOL><INDENT>return<EOL><DEDENT>self.b = b<EOL>self.matching_blocks = self.opcodes = None<EOL>self.fullbcount = None<EOL>self.__chain_b()<EOL>
Set the second sequence to be compared.

        The first sequence to be compared is not changed.

        >>> s = SequenceMatcher(None, "abcd", "bcde")
        >>> s.ratio()
        0.75
        >>> s.set_seq2("abcd")
        >>> s.ratio()
        1.0
        >>>

        SequenceMatcher computes and caches detailed information about the
        second sequence, so if you want to compare one sequence S against
        many sequences, use .set_seq2(S) once and call .set_seq1(x)
        repeatedly for each of the other sequences.

        See also set_seqs() and set_seq1().