code: def replace_interval(self, start, end, new):
          '''Replaces the sequence from start to end with the sequence "new"'''
          if start > end or start > len(self) - 1 or end > len(self) - 1:
              raise Error('Error replacing bases ' + str(start) + '-' + str(end) + ' in sequence ' + self.id)
  
          self.seq = self.seq[0:start] + new + self.seq[end + 1:f replace_interval(self, start, end, new):
          '''Replaces the sequence from start to end with the sequence "new"'''
          if start > end or start > len(self) - 1 or end > len(self) - 1:
              raise Error('Error replacing bases ' + str(start) + '-' + str(end) + ' in sequence ' + self.id)
  
          self.seq = self.seq[0:start] + new + self.seq[end + 1:]
docs: Replaces the sequence from start to end with the sequence "new"