to_time_series.rb

#!/bin/ruby
require 'csv'
file_names = Dir["./*.csv"]
file_names.sort!
lines = []
file_names.each do |path|
  i = 0
  columns_in_header = 0
  IO.readlines(path).each_with_index do |line, i|
    columns_in_header = line.split(',').size if i == 0
    line = line.gsub(/\n/, "")
    line = line.gsub(/\r/, "")
    date = path.gsub("./", "").gsub(".csv", "")
    date =  Date.strptime(date, "%m-%d-%y").strftime("%Y-%m-%d")
    # Some files change the format after some time, so we need to add more padding.
    line += ",," if columns_in_header == 6
    # Appends the date of this entry to the csv
    line += ",#{date}\n"
    # do not append the header of the csv, we will do this at the end.
    lines << line if i != 0
  end
end
# creates an aggregated file
puts lines