r - 合并两个 data.frames 并用 df2 的值替换 df1 某些列的值

Question

我有两个 data.frames，我想合并和替换 df1 某些列的值
df2 的值。在这个工作示例中，只有 3 列。但在原始数据中，
在最终的 data.frame 中应该保留大约 20 列。

NO <- c(2, 4, 7, 18, 25, 36, 48)
WORD <- c("apple", "peach", "plum", "orange", "grape", "berry", "pear")
CLASS <- c("p", "x", "x", "n", "x", "p", "n")
ColA <- c("hot", "warm", "sunny", "rainy", "windy", "cloudy", "snow")
df1 <- data.frame(NO, WORD, CLASS, ColA)
df1

#   NO   WORD CLASS   ColA
# 1  2  apple     p    hot
# 2  4  peach     x   warm
# 3  7   plum     x  sunny
# 4 18 orange     n  rainy
# 5 25  grape     x  windy
# 6 36  berry     p cloudy
# 7 48   pear     n   snow

NO <- c(4, 18, 36)
WORD <- c("patricia", "oliver", "bob")
CLASS <- c("p", "n", "x")

df2 <- data.frame(NO, WORD, CLASS)
df2

#   NO     WORD CLASS
# 1  4 patricia     p
# 2 18   oliver     n
# 3 36      bob     x

我想合并两个 data.frames 并从 df1 替换 WORD 和 CLASS 的值
使用来自 df2 的 WORD 和 CLASS 的值

我的 data.frame 应该是这样的:

#   NO      WORD CLASS   ColA
# 1  2     apple     p    hot
# 2  4  patricia     p   warm
# 3  7      plum     x  sunny
# 4 18    oliver     n  rainy
# 5 25     grape     x  windy
# 6 36       bob     x cloudy
# 7 48      pear     n   snow

Answer 1

尝试这个

auxind<-match(df2$NO, df1$NO)  # Stores the repeated rows in df1
dfuni<-(rbind(df1[,1:3],df2)[-auxind,])  # Merges both data.frames and erases the repeated rows from the first three colums of df1
dfuni<-dfuni[order(dfuni$NO),] # Sorts the new data.frame
df1[,1:3]<-dfuni