using a number as a subdirectory

[LeviFiction]

Hello,

I'm not sure how to handle this with the python client. I'm wanting to grab notes from my books using the Google Books API. But the way the API is designed, in order to get a volume from my private bookshelf I have to call the bookshelf with a number id like this.

HTTP://https://www.googleapis.com/books/v1/mylibrary/bookshelves/**7**/volumes/key=YourAPIKey

Obviously I can't call it like this

services.mylibrary().bookshelves().7().volumes().list()
So is there a method built-in to add the "/7/" portion to the resource that's building the URL in between .bookshelves() and .volumes()?