My Excel document my.xlsx has two Sheets named Sheet1 and Sheet2. I want to read all worksheets in an Excel workbook using fread function from data.table R package. The following code just read the active worksheet. Wonder how to read all worksheets without knowing their names. Thanks
df3 <- data.table::fread("in2csv my.xlsx")
> names(df3)
[1] "A" "B"
> df3
A B
1: 1 2
2: 2 4
3: 3 6
4: 4 8
5: 5 10
I used openxlsx::read.xlsx the last time I needed to read many sheets from an XLSX.
#install.packages("openxlsx")
library(openxlsx)
#?openxlsx::read.xlsx
#using file chooser:
filename <- file.choose()
#or hard coded file name:
#filename <- "filename.xlsx"
#get all the sheet names from the workbook
SheetNames<-getSheetNames(filename)
# loop through each sheet in the workbook
for (i in SheetNames){
#Read the i'th sheet
tmp_sheet<-openxlsx::read.xlsx(filename, i)
#if the input file exists, append the new data;; else use the first sheet to initialize the input file
ifelse(exists("input"),
input<-rbind(input, tmp_sheet),
input<-tmp_sheet)
}
Note: This assumes each worksheet has identical column structure and data types. You may need to standardize\normalize the data (ex. tmp_sheet <- as.data.frame(sapply(tmp_sheet,as.character), stringsAsFactors=FALSE)), or load each sheet into it's own dataframe and pre-process further before merging.