14 DAY TRIAL // Google Reader is about to be shut down, and it's only got a day or so to live. Millions of users will have to find new homes, but there are plenty of alternatives, though none is as good as Reader, unfortunately.
Still, some users are happy just to get their data out and will worry about replacements later. Google makes it possible to export your subscriptions and folders via Google Takeout, but that's hardly the only data Reader has on you.
If you're a longtime user, the entire history of your read items, starred items, shared stories, comments, and so on and so forth, is stored by Google Reader.
But, until now, you couldn't get it out. Thankfully, former Googler and longtime Google Reader maintainer Mihai Parparita has put together a much more comprehensive tool that uses the Google Reader API to export every last piece of data available for your account.
"I've... built the reader_archive tool that dumps everything related to your account in Reader via the 'API.' This means every read item3, every tagged item, every comment, every like, every bundle, etc.," Parparita wrote.
The tool is a collection of Python scripts, and you're going to need to have Python installed on your computer to run them. That's not a problem on Linux, but it means a few more steps on other operating systems.
To get your full Google Reader archive, you need to run reader_archive. The tool itself isn't complicated to use, even if you don't have experience with command-line programs, all you need to do is authorize it.
Parparita also put together a tool (feed_archive) to extract the entire feed archive from Reader, i.e. every feed ever added to Reader by any user. This would be useful in a number of contexts. The Archive Team organization is already working on getting all this data. Finally, to make it possible to browse all the data, there's also the reader_browser tool, which is still incomplete.