将列表列表中的项目分配为数据框的列名

编程问答 2022-05-27

问题描述

我有几个没有变量名称的数据框。他们都是不同的。我有一个列表，其中包含一组与每个数据框一起使用的列名（列表项的类似名称与匹配的数据框）。我想在数据框中分配/使用列名。我尝试用循环做一些事情，然后 lapply 但我就是无法得到它。下面是我正在谈论的一个例子。对于此处不完美的编码和解释，我预先道歉。我确信答案是我应该能够做的。非常感谢任何帮助。

#Activate a package
library(rio)
##################################################
#Create data frames
dir.create("data/")
sec1<- data.frame(x1 = 1:5,x2 =c("L","M","N","O","P"),x3 = c(4,1,9,1))
#########
sec2<- data.frame(x1 = c("A","B","C","D","E"),x2 = 1:5,x3 = c(12,10,29,5))
#########
sec3<- data.frame(x1 = c(100,21,91,53,35),x3 = c("W","X","Y","Z","A"))

#Export into folder as csv file
export(sec1,"data/sec1.csv")
export(sec2,"data/sec2.csv")
export(sec3,"data/sec3.csv")
#Clear out these files for Now
rm(sec1,sec2,sec3)
###############################################
#Create a list of columns names
sec1<-c("A","C")
sec2<-c("AA","BB","CC")
sec3<-c("AAA","BBB","CCC")
#####
listAA<-list(sec1,sec3);listAA
rm(sec1,sec3)
#I was hoping to use loop command or lapply to use the list names for the data frames

解决方法

如果我理解正确，您想将列名添加到 data.frames 列表中。您的代码令人困惑，因为您删除了数据框，然后使用它们的名称作为列名：

sec1 <- data.frame(x1 = 1:5,x2 =c("L","M","N","O","P"),x3 = c(4,1,9,1))
sec2 <- data.frame(x1 = c("A","B","C","D","E"),x2 = 1:5,x3 = c(12,10,29,5))
sec3 <- data.frame(x1 = c(100,21,91,53,35),x3 = c("W","X","Y","Z","A"))
listDTA <- list(sec1=sec1,sec2=sec2,sec3=sec3)
listAA <- list(sec1 = c("A","C"),sec2 = c("AA","BB","CC"),sec3 = c("AAA","BBB","CCC"))

现在使用循环将 listDTA 中的列名称分配给列表 listAA 中的数据框：

n <- length(listDTA)
for (i in seq_len(n)) {
    colnames(listDTA[[i]]) <- listAA[[i]]
}
listDTA
# $sec1
#   A B C
# 1 1 L 4
# 2 2 M 1
# 3 3 N 9
# 4 4 O 0
# 5 5 P 1

# $sec2
#   AA BB CC
# 1  A  1 12
# 2  B  2 10
# 3  C  3 29
# 4  D  4  0
# 5  E  5  5

# $sec3
#   AAA BBB CCC
# 1 100   1   W
# 2  21   2   X
# 3  91   3   Y
# 4  53   4   Z
# 5  35   5   A
columnnamedataframelistrr