'Given a file object to write to and {start/end date, start/end letter} bounds,
generates a CSV report of the appropriate type.'

def write_csv(self, filelike):

    items = self.rows()
    writer = unicodecsv.writer(filelike, encoding='utf-8')
    writer.writerow(self.header())
    for item in items:
        writer.writerow(item)
