Automating importation and naming of a csv file

Question

I am trying to import many csv files from an EPA website. The nomenclature of those csv files is sensible / consistent. Any suggestions on how I can use a loop to automate the importation of the csv files and their naming as dataframes within R?

Right now I'm doing it manually by swapping out the month name in each line of code as illustrated below:


library(tidyverse)

#Download 2013 data

jan_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_jan2013.csv")%>%
  add_column("month"="jan","year"=2013)
feb_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_feb2013.csv")%>%
  add_column("month"="feb","year"=2013)
mar_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_mar2013.csv")%>%
  add_column("month"="mar","year"=2013)
apr_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_apr2013.csv")%>%
  add_column("month"="apr","year"=2013)
may_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_may2013.csv")%>%
  add_column("month"="may","year"=2013)
jun_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_june2013.csv")%>%
  add_column("month"="jun","year"=2013)
jul_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_july2013.csv")%>%
  add_column("month"="jul","year"=2013)
aug_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_aug2013.csv")%>%
  add_column("month"="aug","year"=2013)
sep_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_sept2013.csv")%>%
  add_column("month"="sep","year"=2013)
oct_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_oct2013.csv")%>%
  add_column("month"="oct","year"=2013)
nov_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_nov2013.csv")%>%
  add_column("month"="nov","year"=2013)
dec_13<-read.csv("https://www.epa.gov/sites/default/files/2017-10/rindata_dec2013.csv")%>%
  add_column("month"="dec","year"=2013)

I'd like to set something up where all 12 months are imported, the added column is modified appropriately and the resulting df is named appropriately, by month.

Thanks for the help!

dcsuka · Answer

Read all of the csvs using a vector of months and string concatenation, then set their names, enframe, add a year column, and unnest:

months <- c("jan", "feb", "mar", "apr", "may", "june", "july", "aug", "sept", "oct", "nov", "dec")

dfs <- lapply(months, function(x) read.csv(paste0("https://www.epa.gov/sites/default/files/2017-10/rindata_", x, "2013.csv"))) %>%
  setNames(months) %>%
  enframe(name = "month") %>%
  add_column(year = 2013) %>%
  unnest(value)

Let me know if this works!

Automating importation and naming of a csv file

1 Answers