Python DataFrame：根據條件過濾 dataframe 日期？

Question

我正在嘗試按start_date過濾 df 。

start_date對於每個用戶都是相同的。 如果present_dates中的任何記錄小於start_date ，則必須由用戶過濾掉。

樣本df

                name      present_dates                     start_date
        0       bruno    2021-03-08 10:09:37.623        2021-04-01 10:09:37.623
        1       bruno    2021-05-08 10:09:37.623        2021-04-01 10:09:37.623
        2       bruno    2021-06-08 10:09:37.623        2021-04-01 10:09:37.623
        3       paul     2021-02-24 10:09:37.623        2021-01-25 10:09:37.623
        4       paul     2021-01-15 10:09:37.623        2021-01-25 10:09:37.623
        5       marcus   2021-06-08 10:09:37.623        2021-10-15 10:09:37.623
        6       luke     2021-01-05 10:09:37.623        2021-01-01 10:09:37.623

預計 Output

                name      present_dates                     start_date
        0       bruno    2021-05-08 10:09:37.623        2021-04-01 10:09:37.623
        1       bruno    2021-06-08 10:09:37.623        2021-04-01 10:09:37.623
        2       paul     2021-02-24 10:09:37.623        2021-01-25 10:09:37.623
        3       luke     2021-01-05 10:09:37.623        2021-01-01 10:09:37.623  

Answer 1

您可以使用前面提到的 boolean 索引，也可以使用df.query()例如：

df.query("start_date < present_date")