require "nokogiri"
require "open-uri"
require "pry"

page = Nokogiri::HTML(open("https://www.website_i_want_datas_from.com"))

myscrapp_2 = []

for k in (1..500) do

    ((page.css("div[@class='wrapper']/div/div//ul[k]/li[4]").text() =~ /@/) != nil ? myscrapp_2 << page.css("div[@class='wrapper']/div/div//ul[k]/li[4]").text()
 : myscrapp_2 << page.css("div[@class='wrapper']/div/div//ul[k]/li[5]").text())

    binding.pry
end