def flip(self):
        '''Flip the DNA - swap the top and bottom strands.

        :returns: Flipped DNA (bottom strand is now top strand, etc.).
        :rtype: coral.DNA

        '''
        copy = self.copy()
        copy.top, copy.bottom = copy.bottom, copy.top
        copy.features = [_flip_feature(f, len(self)) for f in copy.features]
        return copy
def flip ( self ) : copy = self . copy ( ) copy . top , copy . bottom = copy . bottom , copy . top copy . features = [ _flip_feature ( f , len ( self ) ) for f in copy . features ] return copy
Flip the DNA - swap the top and bottom strands.

        :returns: Flipped DNA (bottom strand is now top strand, etc.).
        :rtype: coral.DNA