Split data in r and save all the split files in csv

Question

I have a dataset named data

  Model Garage        City    
  Honda      C     Chicago       
 Maruti      B      Boston  
Porsche      A    New York    
  Honda          


        

Answer 1

you could easily use a loop. that shouldn't be a problem with 100k or so lines.

x <- read.table(text = "Model, Garage, City
                   Honda, C, Chicago
                   Maruti, B, Boston
                   Porsche, A, New York
                   Honda, B, Chicago
                   Honda, C, New York", sep = ",", header = TRUE)
x   
#   Model Garage      City
#   Honda      C   Chicago
#  Maruti      B    Boston
# Porsche      A  New York
#   Honda      B   Chicago
#   Honda      C  New York

library(dplyr) 

you just iterate over all unique combinations of Model, Garage and City, filter them from your data.frame and export the temporary data.frame to a csv table.

uni <- unique(x[,c("Model", "Garage", "City")])

for (j in 1:nrow(uni)) {
  i <- uni[j,]
  tmp <- x %>% filter(Model == i$Model, Garage == i$Garage, City == i$City)

  write.table(tmp, paste(i$Model, "_", i$City, "_", i$Garage, ".csv"))
}

Answer 2

Just to add more options, you can use data.table:

library(data.table)
x <- as.data.table(x)
x[, write.table(.SD, paste("path/file_", Model, "_", Garage, "_", City, ".csv", sep = "")), by = c("Model", "Garage", "City")]

Answer 3

# create all combinations of data.frames possible based on unique values of Model, Garage, City
l = split(x, list(x$Model, x$Garage, x$City))

# create csv filrs only if data.frame had any rows in it
lapply(names(l), function(x) if(dim(l[[x]])[1] != 0){write.csv(l[[x]], paste0("path", x,".csv"))})