infoboxer-list-of-areas.rb

require 'infoboxer'

page = Infoboxer.wikipedia.get('List of urban areas by population')

res = page
  .sections(/Urban areas/).tables.first
  .rows[1..-1].map { |r| 
    {
      city: r.cells[2].to_s, 
      country: r.cells.templates.first.name,  # What you see as Japan on page, in page code looks like {{JPN}}
      population: r.cells[4].to_s
    } 
  }

p res.first(3)
# => [{:city=>"Tokyo–Yokohama (Keihin)", :country=>"JPN", :population=>"37,750,000"}, {:city=>"Jakarta (Jabodetabek)", :country=>"IDN", :population=>"30,091,131"}, {:city=>"Delhi (NCR)", :country=>"IND", :population=>"24,998,000"}]