테이블 생성코드 data = [[1, 3, 5, '2019-08-01'], [1, 3, 6, '2019-08-02'], [2, 7, 7, '2019-08-01'], [2, 7, 6, '2019-08-02'], [4, 7, 1, '2019-07-22'], [3, 4, 4, '2019-07-21'], [3, 4, 4, '2019-07-21']] views = pd.DataFrame(data, columns=['article_id', 'author_id', 'viewer_id', 'view_date']).astype({'article_id':'Int64', 'author_id':'Int64', 'viewer_id':'Int64', 'view_date':'datetime64[ns]'}) 문제 해결 코드 1 de..
