Appending many files into 1 dataset

Question

I have many ".csv" files in one folder with names "file1", "file2", "file3", ... "file50". They all have totally the same structure. Expression for reading one file is:

read.csv(file = "file1.csv", delim = ";", dec = ".")

I need to union (append) all these files in one dataset. How to do it in the most short way?

Answer 1

The idea here is to make a table of all your files, then apply the read_csv() function to each of those files (rows of your table) to create a new column with the data from each csv file.

Finally, use bind_rows() on the data column to get your appended dataset. You could call distinct() on the result before doing the bind_rows() call to get the union of all these files (i.e. no duplicates).

For example, this could work:

library(tidyverse)
result <- tibble(fns = dir(path = "C:/Users/ncama/Downloads", pattern = "csv", full.names = T)) %>%
  mutate(data = map(fns, read_csv, show_col_types = F)); result
#> # A tibble: 5 x 2
#>   fns                                          data                 
#>   <chr>                                        <list>               
#> 1 C:/Users/ncama/Downloads/csv1 - Copy (2).csv <spec_tbl_df [1 x 2]>
#> 2 C:/Users/ncama/Downloads/csv1 - Copy (3).csv <spec_tbl_df [1 x 2]>
#> 3 C:/Users/ncama/Downloads/csv1 - Copy (4).csv <spec_tbl_df [1 x 2]>
#> 4 C:/Users/ncama/Downloads/csv1 - Copy.csv     <spec_tbl_df [1 x 2]>
#> 5 C:/Users/ncama/Downloads/csv1.csv            <spec_tbl_df [1 x 2]>

bind_rows(result$data)
#> # A tibble: 5 x 2
#>   A     B    
#>   <chr> <chr>
#> 1 hello world
#> 2 hello world
#> 3 hello world
#> 4 hello world
#> 5 hello world

^{Created on 2022-04-20 by the reprex package (v2.0.1)}

Where obviously you should change the path to the path of your folder. If you all these files have the csv extension, this should work.