Saving hashes to file on Ruby

Question

I\'m just giving my first steps in programming. I have just finished another class in Code Academy. This time I was asked to create a small movie catalog. Here is my questio

Answer 1

If they're simple hashes, a YAML file may be an easy way to do it.

require 'yaml'

# write hash out as a YAML file
movies = { Memento: 1, Primer: 4, Ishtar: 1 }
File.write('movies.yml', movies.to_yaml)

# read back in from file
from_file = YAML.load_file('movies.yml')

# use it
from_file[:Memento]
# => 1 
from_file[:Primer]
# => 4 

Answer 2

You can simply use JSON, like this

require 'json'

FILE_PATH = "catalogue.json"

def load
  data = nil
  File.open(FILE_PATH) do |f|
    data = JSON.parse(f.read)
  end
  data
end

def save(data)
  File.open(FILE_PATH, "w+") do |f|
    f << data.to_json
  end
end

def process
  catalogue = load

  p catalogue

  catalogue["Memento"] = 4
  save(catalogue)
end

process
# => {"Memento"=>3, "Primer"=>4, "Ishtar"=>1}
catalogue = load

p catalogue
# {"Memento"=>4, "Primer"=>4, "Ishtar"=>1}

Answer 3

The best way according to me is using Marshal method as explained here Marshaling The Marshal module dumps an object in a string, which can be written to a file. Reading the file and Marshal.Loading the string gives the original object. Writing to a file can be achieved using Marshal.dump

For example in your code this can be achieved using

movies = {
Memento: 3,
Primer: 4,
Ishtar: 1
}
# dumping:
File.open("test.marshal", "w"){|to_file| Marshal.dump(movies, to_file)}
# retrieving:
p File.open("test.marshal", "r"){|from_file| Marshal.load(from_file)}
#gives you movies = {Memento: 3,Primer: 4,Ishtar: 1}

Another method is explained by @Nick Veys using Yaml it is also used by people a lot.

Similar explanations can be obtained here as well.Closest match I found