Create fake data and write 20,000 CSV file to disk

write_csv_files.R

library(data.table) # for fwrite()
library(stringr)
library(purrr)

# file names we will use when writing 20,000 CSV files to disk
filenames <- paste0("files/", "a_",
                    str_pad(1:20000, width = 5,side = "left", pad = "0"),
                    ".csv")

# some vectors we can sample from to make a table
dates <- c(as.Date("2019-01-01"), as.Date("2020-01-01"), as.Date("2021-01-01"))
weights <- c(31:35)
colors <- c("red", "brown", "black")
pets <- c("cat", "dog", "bird")

# data frame of 5 columns and 1,000 rows
dat <- data.frame(
  date = sample(dates, 1e3, replace = TRUE),
  weight = sample(weights, 1e3, replace = TRUE),
  pet = sample(pets, 1e3, replace = TRUE),
  color = sample(colors, 1e3, replace = TRUE),
  state = sample(state.abb, 1e3, replace = TRUE)
)

# write 20,000 CSV files to disk
walk(.x = filenames, .f = ~fwrite(x = dat, file = .x))