CODEWITHSUNDEEP
rubycsv
eddie tuell
eddie tuell

Reputation: 165

Create a Hash from a CSV-like file

I have a products file listing the item #, products, and price. I would like to read this file and initialize it as a hash with the item #'s being the key and the products and price being the value. Here is my file

199, Shoes, 59.99
211, Shirts, 19.99
245, Hats, 25.99
689, Coats, 99.99
712, Beanies, 6.99

I would like it to look like this.

products = {
  199 =>['Shoes', 59.99],
  211 =>['Shirts', 19.99],
  245 =>['Hats', 25.99],
  689 => ['Coats', 99.99],
  712 => ['Beanies', 6.99]
}

This is what i could come up with which is not really what it want.

products_file = File.open("files.txt")
products_hash = []
while ! products_file.eof?
  product_hash = products_file.gets.chomp
  print product_hash.split(', ')
end

And here is the output that I came up with:

["199", "Shoes", "59.99"]
["211", "Shirts", "19.99"]
["245", "Hats", "25.99"]
["689", "Coats", "99.99"]
["712", "Beanies", "6.99"]

Upvotes: 3

Views: 3333

Answers (2)

steenslag
steenslag

Reputation: 80065

A variation, manipulating the data with CSV's converters:

require 'csv'
products = {}
CSV.foreach('products.csv', {col_sep: ', ', converters: :numeric}) do |row|
  products[row.shift] = row
end
p products
#=> {199=>["Shoes", 59.99], 211=>["Shirts", 19.99], 245=>["Hats", 25.99], 689=>["Coats", 99.99], 712=>["Beanies", 6.99]}

Upvotes: 1

Michael Kohl
Michael Kohl

Reputation: 66837

I saved your data as a CSV file called products.csv and did this:

require 'csv'
products = {}
CSV.foreach("products.csv") do |line| 
  products[line[0].to_i] = [line[1].strip, line[2].to_f]
end
products
#=> {199=>["Shoes", 59.99], 211=>["Shirts", 19.99], 245=>["Hats", 25.99], 689=>["Coats", 99.99], 712=>["Beanies", 6.99]}

The same result can be achieved in a more concise way using each_with_object, but it reads the whole file into memory at once, which may not be a good idea if the file is large:

require 'csv'
products = CSV.read("products.csv").each_with_object({}) do |line, h|
  h[line[0].to_i] = [line[1].strip, line[2].to_f]
end

There's also a more functional approach, as originally suggested by Phrogz:

require 'csv'
products = Hash[ CSV.read('products.csv').map do |row|
  [ row[0].to_i, [row[1].strip,row[2].to_f] ]
end ]

Upvotes: 11

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