Javascript – Get the site's html code with Python and inspect

Is there a solution to enter a site with Python and run a script in the inspect section and get the html of that site. (it is not possible to get the site’s html by get)

I have this script and I tried it manually, I can download the site html with it, but I want to do it automatically.

function myFunction() {
  filename = "dom";
  var html = '',
    node = document.firstChild
  while (node) {
    switch (node.nodeType) {
      case Node.ELEMENT_NODE:
        html += node.outerHTML
        break
      case Node.TEXT_NODE:
        html += node.nodeValue
        break
      case Node.CDATA_SECTION_NODE:
        html += '<![CDATA[' + node.nodeValue + ']]>'
        break
      case Node.COMMENT_NODE:
        html += '<!--' + node.nodeValue + '-->'
        break
      case Node.DOCUMENT_TYPE_NODE:
        // (X)HTML documents are identified by public identifiers
        html +=
          '<!DOCTYPE ' +
          node.name +
          (node.publicId ? ' PUBLIC "' + node.publicId + '"' : '') +
          (!node.publicId && node.systemId ? ' SYSTEM' : '') +
          (node.systemId ? ' "' + node.systemId + '"' : '') +
          '>n'
        break
    }
    node = node.nextSibling
  }


  var file = new Blob([html], {
    type: 'text/html'
  });
  if (window.navigator.msSaveOrOpenBlob) // IE10+
    window.navigator.msSaveOrOpenBlob(file, filename);
  else { // Others
    var a = document.createElement("a"),
      url = URL.createObjectURL(file);
    a.href = url;
    a.download = filename;
    document.body.appendChild(a);
    a.click();
    setTimeout(function () {
      document.body.removeChild(a);
      window.URL.revokeObjectURL(url);
    }, 0);
  }
}
setInterval(myFunction, 5000);