Importing multiple csv files and add year to each file

user_8484885 0
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I'm using the following function to import roughly 10 files from different years (all from the same folder) into r.

ed.attain.places_0_10_18 <-
    list.files(path = "./ed_attainment/",
               pattern = "*.csv", 
               full.names = T) %>% 
    map_df(~read_csv(., col_types = cols(.default = "c")))

This folder (ed_attainment/) contains the following csv files all the way to '17.

ACS_09_5YR_B19301_with_ann.csv
ACS_10_5YR_B19301_with_ann.csv

I want to add the year to each one of these files within the above function. Just importing one csv file the code would be

read_csv("ACS_09_5YR_B19301_with_ann.csv")%>%mutate(year = 09)

such that the year in the filename corresponds with the values in the new "year" variable.

Thanks much!

dplyr csv r
2 Answers

I suggest:

myReadCsv <- function(fullPath){
   # Pull the Year out of the fullPath
  year <- paste0("20", str_match(fullPath, 
                         "ACS_(\\d{2})")[,2])
    # Read csv as you did before
  read_csv(fullPath, col_types = cols(.default = "c")) %>% 
     # Add YEAR in as a column
    mutate(YEAR = year)
}

and then

ed.attain.places_0_10_18 <-
  list.files(path = "./ed_attainment/",
             pattern = "*.csv", 
             full.names = T) %>% 
  map_df(myReadCsv)

NOT RUN

## Because I don't have a directory of CSV files handy. ##

user_60040160

There are various ways to do this but without changing much of your code, you can add an id variable named year in map_df which will have index of the filename. So first file (ACS_09_5YR_B19301_with_ann.csv) would have index as 1, second file (ACS_10_5YR_B19301_with_ann.csv) would have index as 2 and so on.

You can then add 2008 to this index to get year value from 2009-2017. 

list.files(path = "./ed_attainment/",
           pattern = "\\.csv", 
           full.names = TRUE) %>% 
    purrr::map_df(~readr::read_csv(.,col_types = cols(.default = "c")), 
                 .id ='year') %>% 
   dplyr::mutate(year = 2008 + as.integer(year))
user_39629140
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