Show HN: Public Datasets for Machine Learning

I keep saying this, but I feel like gathering correct, valid, and formatted data is the biggest part of machine learning and data analysis these days. Learning the algorithms takes time, but using libraries for learning is decently quick. Getting the data you want to use takes the most time and effort.

Great to see posts and sites like this that share public data for people to learn ML and possibly even result in benefits.

Enron_Corpus - Not a clean dataset for training but a unique resource.

https://en.wikipedia.org/wiki/Enron_Corpus

"The corpus is unique in that it is one of the only publicly available mass collections of real emails easily available for study, as such collections are typically bound by numerous privacy and legal restrictions which render them prohibitively difficult to access"