Read multiple xlsx files with multiple sheets into one R data frame

Question

I have been reading up on how to read and combine multiple xlsx files into one R data frame and have come across some very good suggestions like, How to read multiple xlsx file in R using loop with specific rows and columns, but non fits my data set so far.

I would like R to read in multiple xlsx files with that have multiple sheets. All sheets and files have the same columns but not the same length and NA's should be excluded. I want to skip the first 3 rows and only take in columns 1:6, 8:10, 12:17, 19.

So far I tried:

file.list <- list.files(recursive=T,pattern='*.xlsx')

dat = lapply(file.list, function(i){
    x = read.xlsx(i, sheetIndex=1, sheetName=NULL, startRow=4,
              endRow=NULL, as.data.frame=TRUE, header=F)
# Column select 
    x = x[, c(1:6,8:10,12:17,19)]
# Create column with file name  
    x$file = i
# Return data
    x
  })

  dat = do.call("rbind.data.frame", dat)

But this only takes all the first sheet of every file

Does anyone know how to get all the sheets and files together in one R data frame?

Also, what packages would you recommend for large sets of data? So far I tried readxl and XLConnect.

Answer 1

I would use a nested loop like this to go through each sheet of each file. It might not be the fastest solution but it is the simplest.

require(xlsx)    
file.list <- list.files(recursive=T,pattern='*.xlsx')  #get files list from folder

for (i in 1:length(files.list)){                                           
  wb <- loadWorkbook(files.list[i])           #select a file & load workbook
  sheet <- getSheets(wb)                      #get sheet list

  for (j in 1:length(sheet)){ 
    tmp<-read.xlsx(files.list[i], sheetIndex=j, colIndex= c(1:6,8:10,12:17,19),
                   sheetName=NULL, startRow=4, endRow=NULL,
                   as.data.frame=TRUE, header=F)   
    if (i==1&j==1) dataset<-tmp else dataset<-rbind(dataset,tmp)   #happend to previous

  }
}

You can clean NA values after the loading phase.