Ruby

Very, very new to both Ruby and programming in general, so any feedback or comments would be much appreciated. Daunted by the solutions I've seen!

require 'csv'

def presidents_alive(year_from, year_to)
  results = {}

  CSV.foreach("presidents.csv", encoding:"bom|utf-8", :headers => true, :header_converters => :symbol) do |row|    
    b = row[:birth_date][/\d{4}/].to_i
    d = row[:death_date][/\d{4}/] ? ( row[:death_date][/\d{4}/].to_i ) : 2016 

    (year_from..year_to).each do |year|
      results[year] ||= []
      results[year] << row[:president] if (b..d).include?(year)  
    end
  end
  return results
end

def most_in_year(results)
  results.each do |k,v|
    puts "#{k} - #{v.size} presidents alive" if v.size == (results.values.map {|i| i.size}).max
  end
end

most_in_year(presidents_alive(1733, 2016))

And - assuming I can get the markdown to work - this should be the output:

1822 - 18 presidents alive
1823 - 18 presidents alive
1824 - 18 presidents alive
1825 - 18 presidents alive
1826 - 18 presidents alive
1831 - 18 presidents alive
1833 - 18 presidents alive
1834 - 18 presidents alive
1835 - 18 presidents alive
1836 - 18 presidents alive
1837 - 18 presidents alive
1838 - 18 presidents alive
1839 - 18 presidents alive
1840 - 18 presidents alive
1841 - 18 presidents alive
1843 - 18 presidents alive
1844 - 18 presidents alive
1845 - 18 presidents alive

It's also capable (I think) of returning which presidents are alive on any given year