У меня есть этот фрейм данных:
id action user weight timestamp
830093 opt_in 56610 NaN 2017-01-29T23:03:35.000Z
830095 level_up 56610 NaN 2017-01-29T23:03:36.000Z
2312674 checkout_item 56610 239.99 2017-05-15T23:19:20.000Z
2313301 checkout_item 56610 239.99 2017-05-15T23:19:20.000Z
2315639 checkout 56610 239.99 2017-05-15T23:19:20.000Z
2316158 daily_login 56610 NaN 2017-05-15T23:13:33.000Z
2402783 daily_login 56610 NaN 2017-05-23T10:51:09.000Z
2438779 daily_login 56610 NaN 2017-05-24T01:10:52.000Z
2530543 daily_login 56610 NaN 2017-05-25T22:21:10.000Z
2573416 daily_login 56610 NaN 2017-05-28T01:38:46.000Z
2679591 daily_login 56610 NaN 2017-06-05T09:33:59.000Z
2813275 checkout_reject 56610 NaN 2017-06-15T04:29:02.000Z
2981829 daily_login 56610 NaN 2017-06-26T16:40:56.000Z
3195018 daily_login 56610 NaN 2017-07-11T09:11:35.000Z
3244062 daily_login 56610 NaN 2017-07-14T17:46:04.000Z
3311904 daily_login 56610 NaN 2017-07-20T00:50:08.000Z
3313849 checkout 56610 459.20 2017-07-20T09:17:12.000Z
3313852 checkout_item 56610 459.20 2017-07-20T09:17:12.000Z
3764903 daily_login 56610 NaN 2017-08-18T10:24:23.000Z
3781360 checkout_update 56610 459.20 2017-08-19T07:10:25.000Z
3781363 checkout_item 56610 459.20 2017-08-19T07:10:25.000Z
3781366 checkout_accept 56610 NaN 2017-08-19T07:10:26.000Z
4095024 daily_login 56610 NaN 2017-09-05T07:31:44.000Z
4557587 daily_login 56610 NaN 2017-10-01T19:40:10.000Z
4652940 daily_login 56610 NaN 2017-10-06T17:36:52.000Z
5455155 checkout_item 56611 NaN 2017-11-17T00:35:29.000Z
5455155 checkout_update 56611 NaN 2017-11-17T00:35:29.000Z
5455155 checkout_accept 56611 NaN 2017-11-17T00:35:41.000Z
5455155 daily_login 56611 NaN 2017-11-18T00:31:27.000Z
5455155 daily_login 56611 NaN 2017-11-19T00:37:19.000Z
5455155 checkout_item 56611 100.00 2017-11-19T00:35:29.000Z
5455155 checkout_item 56611 100.00 2017-11-17T00:35:29.000Z
5455155 checkout 56611 100.00 2017-11-17T00:35:29.000Z
5455155 daily_login 56610 NaN 2017-11-19T00:38:25.000Z
Я хочу использовать панд только для подсчета checkout_item-s, который произошел вместе с checkout
user: 56610 num_of_checkout_item: 3
user: 56611 num_of_checkout_item: 2
У кого-нибудь есть идеи?