R

Question

我有两个行数不等的数据框：

df1

Label   Country    Year
NU      Germany    1999
BU      Italy      1945
LU      France     2009
KM      Sweden     1998
NU      Germany    1999

和

df2

Make     Label     
X1       NU
X2       BU
X3       NU
X4       NU
X5       KM

我想做的是匹配＆＃34;标签＆＃34;并最终得到以下结论：

Make   Label    Country     Year
X1       NU     Germany     1999
X2       BU     Italy       1945
X3       NU     Germany     1999
X4       NU     Germany     1999
X5       KM     Sweden      1998

Answer 1

 a=merge(df2,df1,by="Label")
 a[!duplicated(a),]
   Label Make Country Year
 1    BU   X2   Italy 1945
 2    KM   X5  Sweden 1998
 3    NU   X1 Germany 1999
 5    NU   X3 Germany 1999
 7    NU   X4 Germany 1999