code: def gc(self):
          '''Find the frequency of G and C in the current sequence.'''
          gc = len([base for base in self.seq if base == 'C' or base == 'G'])
          return float(gc) / len(selff gc(self):
          '''Find the frequency of G and C in the current sequence.'''
          gc = len([base for base in self.seq if base == 'C' or base == 'G'])
          return float(gc) / len(self)
docs: Find the frequency of G and C in the current sequence.