def main(request):
    page=str(1)
    d3 = requests.get('https://d3.ru/api/posts/?sorting=rating&threshold_date=day&page='+page).json()

page=str(2)
page=str(3)
page=str(4)

$(window).scroll(function () {
    if ($(window).scrollTop() + $(window).height() == $(document).height()) {
        alert("uzhe dno");
});

$.ajax({
     url: "{% url 'main' %}",
     type: "GET",
     //call main
 });

$(window).scroll(function() {
    if($(window).scrollTop() == $(document).height() - $(window).height()) {
           // ajax call get data from server and append to the div
    }
});