How to split a data frame by row into multiple data frames and then export them to excel? R

Question

This is the data I am working with

Sales <- data.frame(State  = c("New York", "New Jersey", "Texas","New Mexico","California",
                                "Kansas","Florida","Alaska","Montana", "Maine"),
                     
                  Units = c(455,453,125,135,135,568,451,125,215,314),
                  
                  Sales = c("20000","12530","51110","54110","65000",
                            "58220","54612","45102","45896","12510"),
                             
                  ManagerName = c("Chip","Kelly","Steve","Young","Troy",
                                  "Aikman", "Chad","Pennington","Mike","Vick")
                  
)

My end goal is to have 10 different excel files for each "State".

I know I can do something like

#Seperate by State
library(dplyr)
NewYork <- Sales %>% filter(State == "New York") 

#Save to excel
library(xlsx)
write.xlsx(NewYork, file="NewYork-Sales-November2020.xlsx", 
           sheetName="NewYork")

But the problem is that I have over 50+ rows and do not want to have 50 commands to filter by state and then another 50 commands to write an excel file.

Is there a more efficient way to save each row "State" into an different excel files?

Answer 1

The following does what the question asks for, I have tested it with the posted data.

1. split the data by State;
2. create a workbook;
3. add work sheets to the workbook;
4. write each sub-data.frame to the workbook;
5. save everything to disk.

The sheets are named by State.

library(openxlsx)

sp <- split(Sales, Sales$State)
names(sp) <- ifelse(nchar(names(sp)) > 31, substr(names(sp), 1, 31), names(sp))
wb <- createWorkbook(creator = "FruityPebblePug")
lapply(seq_along(sp), function(i){
  addWorksheet(wb, sheetName = names(sp)[[i]])
})
lapply(seq_along(sp), function(i){
  writeData(wb, sheet = names(sp)[[i]], sp[[i]])
})
saveWorkbook(wb, "Sales-November2020.xlsx")

---

As noted in comments, if the sheets names have too many characters, exceding Excel's 31 characters limit, the following will name the sheets "State 1", "State 2", etc.

sp <- split(Sales, Sales$State)
wb <- createWorkbook(creator = "FruityPebblePug")
lapply(seq_along(sp), function(i){
  addWorksheet(wb, sheetName = paste("State", i))
})
lapply(seq_along(sp), function(i){
  writeData(wb, sheet = paste("State", i), sp[[i]])
})
saveWorkbook(wb, "Sales-November2020_b.xlsx")