Looking for an Answer - Trying to leave the Dock

Is Docker adequate for developing during, or is it mainly used after an application has been developed? The reason I ask is that I can’t seem to find any lessons that provide actual instruction past running an image and a few other docker commands. Specifically, I am trying to learn web development. One of the docker tutorials I did showed how files that get created in the container, disappear when the container stops unless they get committed. So if I am creating some web files, and forget to commit them, all that gets lost?

I tried Vagrant, and thought it was pretty nice how I could keep my files on my computer and then Vagrant up when I want to work on them. I don’t see how to even pull a directory into my editor, since I am not even sure how to find the directory on my hard drive. I suspect it has to do with volumes…?

I will say the Documentation is written very well, and beats most of the tutorials I’ve found, but even then it kind of gets confusing. For example, the web development section shows how to get a flask up and running, but then nothing on how to actually develop within the flask app, and that is basically what I am trying to learn…what to do after getting an image up and running.