PLEASE NOTE: Sunpower recently sent out an email stating that they will be switching to an "app-based" system. They would want you to download and install their mobile app, which would then give you access to their website. Yeah, no.
Mobile apps give companies a LOT of your info, far more than if you just used a browser to look at your site, and far more than I'd prefer to give a company I bought solar panels from. Plus, I found that their site has gotten progressivly worse and worse about letting me track my production and status.
To that end, I've moved the old python script under legacy, and do not plan on updating it or try to figure out how to get what I need out of their godforsaken site.
Instead I STRONGLY urge you to use the direct access method of getting data out of the sunpower controller box.
You'll get far more info, more timely, and accurately than you will out of trying to sniff their site, plus you won't have to give them any info.
In fact, you can probably just block the controller device from the internet at that point, which is probably a good idea anyway.