Read in data spread across multiple .csv files or multiple sheets of .xlsx files.

read-multiple.R

# Read in multiple .csv files with the same structure (same column names, numbers of columns, types of data in each column) and join them into a single data frame:


library(readr)
library(purrr)
root <- "path/to/where/my/data/is/"
file_paths <- list.files(root, pattern = "*.csv", full.names = TRUE)

#set the names of the file_paths vector, here I'll just use the file names, but you can use whatever
names(file_paths) <- list.files(root, pattern = "*.csv")

#read them all and join them
df <- map_df(file_paths, read_csv, .id = "filename")

# Read in multiple sheets of a .xlsx file and join into a single dataframe, extracting the sheet names as a column.

library(readxl)
library(purrr)
library(dplyr)
my_wkbk <- "~/Documents/example.xlsx" #replace with path to your excel workbook.
shts <- excel_sheets(my_wkbk) #gets sheet names
df <- 
  map(shts, ~read_excel(my_wkbk, sheet = .x)) %>%
  set_names(shts) %>%
  bind_rows(.id = "sheet_name")
  
#or, if you don't care about extracting the sheet names and including them in your data frame...
df <- map_df(shts, ~read_excel(my_wkbk, sheet = .x))