Question

当时我尝试了 group ffill，但没有任何效果。 :(

如何基于名为“Rec”的空白列使用填充。因此，如果此列为空，则在“Rec”列上填充先前的值，然后将“Loc1”和 Loc 也替换为先前的值？

这是我的 df：

+--------+----------+----------------------------+---------+------------+
| Lot    | Rec      | Part                       | Loc1    | Loc        |
+--------+----------+----------------------------+---------+------------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM  |
+--------+----------+----------------------------+---------+------------+
| Y19105 |          | PHEMT6_BGATE_70NM_EBEAM.05 | B_PC    | B_PC_STOCK |
+--------+----------+----------------------------+---------+------------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM  |
+--------+----------+----------------------------+---------+------------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM  |
+--------+----------+----------------------------+---------+------------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM  |
+--------+----------+----------------------------+---------+------------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM  |
+--------+----------+----------------------------+---------+------------+
| Y19105 |          | PHEMT6_BGATE_70NM_EBEAM.05 | B_PC    | B_PC_STOCK |
+--------+----------+----------------------------+---------+------------+
| Y19105 |          | PHEMT6_BGATE_70NM_EBEAM.05 | B_PC    | B_PC_STOCK |
+--------+----------+----------------------------+---------+------------+
| Y19105 |          | PHEMT6_BGATE_70NM_EBEAM.05 | B_PC    | B_PC_STOCK |
+--------+----------+----------------------------+---------+------------+

我想要的输出：

+--------+----------+----------------------------+---------+-----------+
| Lot    | Rec      | Part                       | Loc1    | Loc       |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+
| Y19105 | BIPA6.02 | PHEMT6_BGATE_70NM_EBEAM.05 | B_EBEAM | B_F_EBEAM |
+--------+----------+----------------------------+---------+-----------+

非常感谢您的帮助！

Answer 1

IIUC 如果 Loc1 列是 Loc，您可以尝试将 NaN 和 Rec 值更改为 NaN，然后使用 ffill在整个 DataFrame 上。

试试这个：

df.loc[df['Rec'].isnull(), ['Loc1', 'Loc']] = np.nan
df.ffill()

Python Pandas：根据其他空白列的条件使用填充

1 个答案: