User Review Datasets
These datasets below contain reviews from Rotten Tomatoes, Amazon, TripAdvisor, Yelp, Edmunds.com, and so on. Here are some of the many datasets available out there:
Consumer Reviews of Amazon Products
A list of over 34,000 reviews of Amazon products like the Kindle, Fire TV, etc
100K Coursera's Course Reviews Dataset
100K+ Scraped ...
Tweet Sentiment Extraction
Kaggle supports a variety of dataset publication formats.
Kaggle Twitter Datasets
You need to have an account to download the datasets. You can find the code for preprocessing in the kernels tab.
You'd have to piece it together, but Project Euler has many solutions to the same problems hosted on github
You can get the text of the problems with the URL
and also some machine readable info from the questions: https://projecteuler.chat/viewtopic.php?t=3003