If you do need to execute Javascript from your scraper, you'll want use full headless browser to do your scraping.
This may not matter for the sites that you are working with, but more and more sites are relying on Javascript to function, so you may find that you eventually need a scraper that can run Javascript.
That is, if a page uses Javascript to load some dynamic content and then display it, this content will not be available to you from your scraper. Install the Web Scraping Assistant in your Chrome, Edge, Firefox or Opera browser to make creating scrapes in GrabzIts Online Web Scraper Tool easier than. The biggest difference between scraping directly in Python using BeautifulSoup or something similar is that the basic Python web scrapers will not execute active content on a page. As its using Webkit its rendering behaviour is exactly like Google Chrome.
You can also inject custom JS for example jQuery on any of the pages you want to scrape and use it to access the dom and export out desired data. You should be able to log in to sites and services and download the content that you are interested in. Web scraping made easy a powerful and free Chrome extension for scraping websites in your browser, automated in the cloud, or via API. It provides JS interface to load pages, clicking on buttons etc much like you have in a browser. If you are using a scraping tool that manages a web session for you, you should be able to get most things done using a scraper.