Apply function to files from different folders (R) - r

Question

I have discovered R a couple of years ago and it has been very handy to clean up dataframes, prepare some data and to handle other basic tasks.
Now I would like to try using R to apply basic treatments but on many different files stored in different folders at once.
Here is the script I would like to improve into one function that would loop through my folder "dataset_2006" and "dataset_2007" to do all the work.
library(dplyr)
library(readr)
library(sf)
library(purrr)
setwd("C:/Users/Downloads/global_data/dataset_2006")
shp2006 <- list.files(pattern = 'data_2006.*\\.shp$', full.names = TRUE)
listOfShp <- lapply(shp2006, st_read)
combinedShp <- do.call(what = sf:::rbind.sf, args=listOfShp)
#import and merge CSV files into one data frame
folderfiles <- list.files(pattern = 'csv_2006_.*\\.csv$', full.names = TRUE)
csv_data <- folderfiles %>%
set_names() %>%
map_dfr(.f = read_delim,
delim = ";",
.id = "file_name")
new_shp_2006 <- merge(combinedShp, csv_data , by = "ID") %>% filter(label %in% c("AR45T", "GK879"))
st_write(new_shp_2006 , "new_shp_2006.shp", overwrite = TRUE)
setwd("C:/Users/Downloads/global_data/dataset_2007")
shp2007 <- list.files(pattern = 'data_2007.*\\.shp$', full.names = TRUE)
listOfShp <- lapply(shp2007, st_read)
combinedShp <- do.call(what = sf:::rbind.sf, args=listOfShp)
#import and merge CSV files into one data frame
folderfiles <- list.files(pattern = 'csv_2007_.*\\.csv$', full.names = TRUE)
csv_data <- folderfiles %>%
set_names() %>%
map_dfr(.f = read_delim,
delim = ";",
.id = "file_name")
new_shp_2007 <- merge(combinedShp, csv_data , by = "ID") %>% filter(label %in% c("AR45T", "GK879"))
st_write(new_shp_2007 , "new_shp_2007.shp", overwrite = TRUE)

Answer 1

This is easy to achieve with a for-loop to loop over multiple items. To allow us to use wildcards, we can also add the function Sys.glob():
myfunction <- function(directories) {
for(dir in Sys.glob(directories)) {
# do something with a single dir
print(dir)
}
}
# you can specify multiple directories manually:
myfunction(c('C:/Users/Downloads/global_data/dataset_2006',
'C:/Users/Downloads/global_data/dataset_2007'))
# or use a wildcard to automatically get all files/directories that match the pattern:
myfunction('C:/Users/Downloads/global_data/dataset_200*')