假如有兩個data frame,
xdata :
name | cost |
A | 7.5 |
B | 9 |
C | 6.5 |
ydata :
index | name | amount |
1 | A | 10 |
2 | B | 14 |
3 | C | 3 |
4 | A | 4 |
5 | A | 15 |
6 | C | 9 |
7 | B | 12 |
8 | C | 6 |
9 | A | 7 |
如何能在 ydata, 做出以下效果呢
index | name | amount | cost |
1 | A | 10 | 7.5 |
2 | B | 14 | 9 |
3 | C | 3 | 6.5 |
4 | A | 4 | 7.5 |
5 | A | 15 | 7.5 |
6 | C | 9 | 6.5 |
7 | B | 12 | 9 |
8 | C | 6 | 6.5 |
9 | A | 7 | 7.5 |