Question

    x["next_dtScraped"] = 
if x["away_team"] == x["away_team"].shift(-1):
    x["dtScraped"].shift(-1)
else:
    None

所以基本上我想要创建一个列，它会返回一列的下一行，但前提是另一列的行等于该列的下一行。由于语法错误，上面的代码无法正常工作。我不确定这是否可行。

+--------+---------------+-------------------+---------------------+---------------------+
|        |   home_team   |     away_team     |      dtScraped      |   next_dtScraped    |
+--------+---------------+-------------------+---------------------+---------------------+
|  81965 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 17:40:48 | 2017-09-26 17:54:38 |
|  76817 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 17:54:38 | 2017-09-26 17:56:05 |
| 236234 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 17:56:05 | 2017-09-26 18:04:43 |
| 192767 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:04:43 | 2017-09-26 18:08:38 |
|  13448 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:08:38 | 2017-09-26 18:17:56 |
|  38306 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:17:56 | 2017-09-26 18:23:14 |
| 106907 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:23:14 | 2017-09-26 18:36:36 |
| 235751 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:36:36 | 2017-09-26 18:45:56 |
| 143897 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:45:56 | 2017-09-26 18:47:34 |
| 206117 | APOEL Nicosia | Tottenham Hotspur | 2017-09-26 18:47:34 | 2017-09-28 19:22:49 |
| 112775 | AS Monaco     | Besiktas JK       | 2017-09-28 19:22:49 | 2017-09-28 19:37:41 |
| 128744 | AS Monaco     | Besiktas JK       | 2017-09-28 19:37:41 | 2017-09-28 19:49:06 |
| 238778 | AS Monaco     | Besiktas JK       | 2017-09-28 19:49:06 | 2017-09-28 19:54:15 |
|  37271 | AS Monaco     | Besiktas JK       | 2017-09-28 19:54:15 | 2017-09-28 20:13:15 |
|  81647 | AS Monaco     | Besiktas JK       | 2017-09-28 20:13:15 | 2017-09-28 20:17:44 |
|  65930 | AS Monaco     | Besiktas JK       | 2017-09-28 20:17:44 | 2017-09-28 20:20:31 |
|  45845 | AS Monaco     | Besiktas JK       | 2017-09-28 20:20:31 | 2017-09-28 20:21:50 |
| 110165 | AS Monaco     | Besiktas JK       | 2017-09-28 20:21:50 | 2017-09-28 20:35:16 |
|   4856 | AS Monaco     | Besiktas JK       | 2017-09-28 20:35:16 | 2017-09-28 20:40:36 |
| 148769 | AS Monaco     | Besiktas JK       | 2017-09-28 20:40:36 | 2017-09-28 20:54:01 |
|  34760 | AS Monaco     | Besiktas JK       | 2017-09-28 20:54:01 | 2017-09-28 21:02:34 |
| 182633 | AS Monaco     | Besiktas JK       | 2017-09-28 21:02:34 | 2017-09-28 21:13:20 |
| 230996 | AS Monaco     | Besiktas JK       | 2017-09-28 21:13:20 | 2017-09-28 21:20:41 |
|  66761 | AS Monaco     | Besiktas JK       | 2017-09-28 21:20:41 | 2017-09-28 21:25:49 |
| 243059 | AS Monaco     | Besiktas JK       | 2017-09-28 21:25:49 | 2017-09-28 21:43:19 |
+--------+---------------+-------------------+---------------------+---------------------+

所以我希望，当球队改变时，不要从前一支球队获得价值。因此索引206117，APOEL x托特纳姆的最后一行在列__ttScraped

列中将为空

Answer 1

import numpy as np
x["next_dtScraped"] = np.where(x["away_team"] == x["away_team"].shift(-1),x["dtScraped"].shift(-1),None)

Answer 2

您可以使用reduce：

mask = x["away_team"] == x["away_team"].shift(-1)
mask = reduce(lambda x,y: x and y, mask)
if mask:
    x["dtScraped"].shift(-1)
else:
    None

x["away_team"] == x["away_team"].shift(-1)给你一个布尔列表，所以使用reduce你可以看出它是否严格等于。

对于您的错误我不知道您尝试做什么，但您应该发布错误，以便我们知道如何提供帮助。

编辑：想想我的语法错误是什么，试试这个：

x["next_dtScraped"] = x["dtScraped"].shift(-1) if (x["away_team"] == x["away_team"].shift(-1))     else        None

Answer 3

这应该这样做：

df["next_dtScraped"] = df["next_dtScraped"].apply(lambda x: df["dtScraped"].shift(-1) if df["away_team"] == df["away_team"].shift(-1) else x)

或者：

x["next_dtScraped"] = x.apply(lambda c: c["dtScraped"].shift(-1) if c["away_team"] == c["away_team"].shift(-1) else None)

不确定你需要哪一个：）

如果条件在熊猫

3 个答案: