如何使用值中的名稱列表從全局環境調用數據框

Question

我在全局環境中使用了一組數據名

setwd("D:/dir/")

filenames <- list.files(pattern=".*csv")

for(i in filenames){
  filepath <- file.path(paste(i,sep=","))

  assign(i, read.csv(filepath, sep = ",", header=TRUE))

}

現在我想在文件名（abc.csv，qwe.csv，xyz.csv）中分配名稱作為for循環中的數據幀，如下所示

funct = function(x)
{
  for (i in substr(unique(x),1,3))

    i  <# create df name by assign 1st dataframe name from filenames# >  =  i <from global environment>
    male<-i[which(i$Level == "male"),]
    male$tot_sal = male$sal+male$bonus
    assign('male',male,envir=parent.frame()) #repeat loop for all 3 filename
}

funct(filenames)

提前致謝

Answer 1

我試圖了解您的代碼及其背后的想法。

我使用了列表方法和 tidyverse/dplyr 解決方案

library(tidyverse)
setwd("D:/dir/")    
filenames <- list.files(pattern=".*csv")

# read your files but store them in a list, where the key is the filename
my_files <- list()
for(i in filenames){
  filepath <- file.path(paste(i,sep=","))
  my_files[[i]]<- read.csv(filepath, sep = ",", header=TRUE)
}

# iterate over each file/df, filter for male and calculate the total
my_male_tot_list <- lapply(my_files, function(x){    
  x %>% 
    filter(Level == 'male') %>% # first filter for only males (i guess that is what you want to do)
    mutate(tot_sal = sal+bonus) # create a new column with the tot_sal
})

由於我不確定這是否正是您想要檢索的內容，如果您想要一些不同的東西，請隨時發表評論。