有两个数据框:
d1:id city position
1 NY manager
2 NY manager
3 NY manager
4 NY Engineer
5 LA Engineer
6 LA Designer
d2:
team city position
a NY manager
a NY manager
b NY Engineer
b LA Engineer
我需要通过“城市”和“职位”左连接d1和d2,但是我不想保留所有匹配项。d1的形状不应该改变。但是当我这样做时:
d1.merge(d2, how = "left", on = ["city", "position"])
我得到了所有可能的匹配项,但我需要选择其中一些并保持d1的形状不变
所以期望的结果是:
team city position id
a NY manager 1
a NY manager 2
b NY Engineer 4
b LA Engineer 5
df1必须被更新并变成这样:
id city position
3 NY manager
6 LA Designer
我该怎么做呢?提前感谢。