Wrapper for csv reader to give len() capabilities. *** Doesn't work as expected. ***

csv_reader_wrapper.py

class CsvReaderWrapper(object):
    def __init__(self, csv_file, **kwargs):
        self._csv_file = csv_file
        self._reader = csv.reader(csv_file, **kwargs)

    def __len__(self):
        pos = self._csv_file.tell()
        self._csv_file.seek(0)
        items = 0
        for items, _ in enumerate(self._reader):
            pass
        self._csv_file.seek(pos)
        return items

    def __iter__(self):
        return self

    def next(self):
        return self._reader.next()