def __next__(self):
        """
        Implement next as file does (like readline, except raises StopIteration
        at EOF)
        """
        nextline = self.readline()
        if nextline:
            return nextline
        raise StopIteration()

        Implement next as file does (like readline, except raises StopIteration
        at EOF)
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/zipstream.py