This is a great start, and I find your code extremely easy to read.

I might suggest some example code for more advanced methods of data ingestion. All the code I see uses feed_dict, which is certainly the most straightforward, but once you start to try to ingest larger out-of-core datasets or use distributed tf, things get exceptionally complicated (to me at least).

Some simple-ish code with queue runners and the new Dataset API would really be helpful.