How to save a hash into a CSV

Question

I am new in ruby so please forgive the noobishness.

I have a CSV with two columns. One for animal name and one for animal type. I have a hash with all the keys being animal names and the values being animal type. I would like to write the hash to the CSV without using fasterCSV. I have thought of several ideas what would be easiest.. here is the basic layout.

require "csv"

def write_file
  h = { 'dog' => 'canine', 'cat' => 'feline', 'donkey' => 'asinine' }

  CSV.open("data.csv", "wb") do |csv|
    csv << [???????????]
  end
end

When I opened the file to read from it I opened it File.open("blabla.csv", headers: true) Would it be possible to write back to the file the same way?

Answer 1

If you want column headers and you have multiple hashes:

require 'csv'
hashes = [{'a' => 'aaaa', 'b' => 'bbbb'}]
column_names = hashes.first.keys
s=CSV.generate do |csv|
  csv << column_names
  hashes.each do |x|
    csv << x.values
  end
end
File.write('the_file.csv', s)

(tested on Ruby 1.9.3-p429)