How to parse what the browser shows (not the source of the site)?

Question

Django

Site source snippet:

<select>
    <option>1</option>
</select>

Code via inspector in Mozilla:

<select>
    <option>1</option>
    <option>2</option>
    <option>3</option>
    <option>4</option>
</select>

When viewed through a browser, new options are added via JS. My parser is parsing the source, how do I parse the version shown by the browser? For certain, it is necessary to emulate the user or the browser? Send headers?

Answer 1

selenium-python.readthedocs.org/en/latest/getting-...

Answer 2

here for scrapy there is a link https://github.com/scrapinghub/scrapy-splash that downloads the code, passes it through js execution and only then sends it for disassembly, just your case, relatively speaking, emulates a web browser