Question

我有几个数据框。在每个数据框中都有一个名为Current.Net.Price的列。我想将列名更改为不同的名称。因此我有两个清单：

Names <- c("name1","name2","name3","name4","name5")
dfList <- list(df1,df2,df3,df4,df5)

我试过这样的事情：

i=1
for (df in dfList) {
  names(df)[names(df) == "Current.Net.Price"] <- Names[i]
  i<-i+1
}

但是当我打电话时

View(dfList$df2)

该列仍然名为Current.Net.Price

有人可以帮帮我吗？：）

Answer 1

检查这个简单但类似的例子。这是关于如何访问dfList以提取有关data.frames名称的信息的全部内容。

 # data frames
dt1 = data.frame(x = 1:3,
                     y = 5:7)

dt2 = data.frame(x = 1:4,
                     z = 5:8)

dt3 = data.frame(y = 1:10,
                 x = 21:30)


Names = c("A","B","C")
dfList <- list(dt1,dt2,dt3)


for (i in 1:length(dfList)) {

  names(dfList[[i]])[names(dfList[[i]])=="x"] = Names[i]

}

Answer 2

我相信当你像那样循环（循环遍历列表/向量中的项目）时，原始对象不会更新。如，

l <- 1:5
for (i in l) {
  i <- 3
}
l
# [1] 1 2 3 4 5

以下适用于我。

df1 <- data.frame("x" = rnorm(5),"Current.Net.Price"=1:5)
df2 <- data.frame("x" = rnorm(5),"Current.Net.Price"=1:5)
df3 <- data.frame("x" = rnorm(5),"Current.Net.Price"=1:5)
df4 <- data.frame("x" = rnorm(5),"Current.Net.Price"=1:5)
df5 <- data.frame("x" = rnorm(5),"Current.Net.Price"=1:5)

Names <- c("name1","name2","name3","name4","name5")
dfList <- list(df1=df1,df2=df2,df3=df3,df4=df4,df5=df5)


for (i in 1:5) {
  names(dfList[[i]])[names(dfList[[i]]) == "Current.Net.Price"] <- Names[i]
}

sapply(dfList, colnames)

#      df1     df2     df3     df4     df5
# [1,] "x"     "x"     "x"     "x"     "x"
# [2,] "name1" "name2" "name3" "name4" "name5"

循环遍历数据帧列表

2 个答案: