Fully authorize a local application using OAuth for tumblr

I'm trying to write a program that runs only locally and that interacts with the tumblr-API, including the parts that require OAuth.

I thought about letting the user authorizing my application by opening a webbrowser (with pythons webbrowser-package) with the authorization page of tumblr in it. Problem is that the validation-key, a key part in the OAuth-process that I need to have access to in my application, is passed as an argument in the URL where the user is redirected to after he grants my application access.

Of course I don't have access to a url inside a webbrowser in my application, so my question is: Is there any way I can grant my application access in another way, or will I have to run a webserver just so I can store my validation key temporarily and then pass it to my application? Maybe embed the site using an iframe on a site that is stored on a hard drive? I'm not a webdev, I can't tell.

I have seen this and this answer which both suggest to let the redirect-url be "localhost/whatever" so the user can copy the URL of that and insert it back into the application. I am wondering if there is another solution to this?