Question

我有一个Pandas dataFrame，其列为Date：

    ID  Amount   raw-Date   ZIP transaction-ID  Date    flag
749     145552  $100.00 1/15/2018   27614-7901  1342-P0192-F43  1/15/2018   1.0
1307    145552  $100.00 3/15/2018   27614-7901  1342-P0192-F43  3/15/2018   1.0
1672    145552  $100.00 2/15/2018   27614-7901  1342-P0192-F43  2/15/2018   1.0
3508    145552  $100.00 4/15/2018   27614-7901  1342-P0192-F43  4/15/2018   1.0
4144    145552  $250.00 4/24/2018   27614-7901  1234-O8910-B32  4/24/2018   1.0
4145    145552  $100.00 4/24/2018   27614-7901  1234-O8910-B32  4/24/2018   1.0
4787    145552  $100.00 5/15/2018   27614-7901  1342-P0192-F43  5/15/2018   1.0
8350    145552  $212.44 12/21/2018  27614-7901  1342-P0192-F43  12/21/2018  1.0

当我按日期列对它们进行排序时，即使用data.sort_values('Date')，我得到：

ID  Amount   raw-Date   ZIP transaction-ID  Date    flag
749     145552  $100.00 1/15/2018   27614-7901  1342-P0192-F43  1/15/2018   1.0
8350    145552  $212.44 12/21/2018  27614-7901  1342-P0192-F43  12/21/2018  1.0
1672    145552  $100.00 2/15/2018   27614-7901  1342-P0192-F43  2/15/2018   1.0
1307    145552  $100.00 3/15/2018   27614-7901  1342-P0192-F43  3/15/2018   1.0
3508    145552  $100.00 4/15/2018   27614-7901  1342-P0192-F43  4/15/2018   1.0
4144    145552  $250.00 4/24/2018   27614-7901  1234-O8910-B32  4/24/2018   1.0
4145    145552  $100.00 4/24/2018   27614-7901  1234-O8910-B32  4/24/2018   1.0
4787    145552  $100.00 5/15/2018   27614-7901  1342-P0192-F43  5/15/2018   1.0

其中显然将日期排序为字符串。我尝试了pd.to_datetime(data['Date'])，并再次得到了相同的排序结果：

    ID  Amount  raw-Date    ZIP Appeal ID   Date    flag 
749     145552  $100.00 1/15/2018   27614-7901  1342-P0192-F43  2018-01-15  1.0
8350    145552  $212.44 12/21/2018  27614-7901  1342-P0192-F43  2018-12-21  1.0
1672    145552  $100.00 2/15/2018   27614-7901  1342-P0192-F43  2018-02-15  1.0
1307    145552  $100.00 3/15/2018   27614-7901  1342-P0192-F43  2018-03-15  1.0
3508    145552  $100.00 4/15/2018   27614-7901  1342-P0192-F43  2018-04-15  1.0
4144    145552  $250.00 4/24/2018   27614-7901  1234-O8910-B32  2018-04-24  1.0
4145    145552  $100.00 4/24/2018   27614-7901  1234-O8910-B32  2018-04-24  1.0
4787    145552  $100.00 5/15/2018   27614-7901  1342-P0192-F43  2018-05-15  1.0

感谢您的帮助。

Answer 1

您的数据具有重复的列名Date，因此不建议使用。在这种情况下：df['Date']将给出一个包含两列的数据框，而pd.to_datetime(df['Date'])将失败。

也就是说，您可以执行apply：

df['Date'] = df['Date'].apply(pd.to_datetime)

之后，df.Date.dtypes会给出：

Date    datetime64[ns]
Date    datetime64[ns]
dtype: object

将字符串日期转换为熊猫的datetime格式

1 个答案: