code: def reverse_complement( self ):
          
          rval = copy( self )
          # Conveniently enough, reversing rows and columns is exactly what we
          # want, since this results in A swapping with T and C swapping with G.
          rval.values = self.values[::-1,::-1].copy()
          return rval
docs: Create the reverse complement of this matrix. The result probably
          only makese sense if the alphabet is that of DNA ('A','C','G','T').