Hacker News on 31 December 2019

• IRS Reforms Free File Program, Drops Agreement Not to Compete with TurboTax
• Show HN: A tiny isometric city builder in JavaScript
• Show HN: One Page Calendar 2020
• New Material Breaks World Record Turning Heat into Electricity
• Ask HN: Full-on machine learning for 2020, what are the best resources?
• Doing a database join with CSV files
• All DMCA notices filed against TorrentFreak in 2019 were bogus
• The impact of cannabis access laws on opioid prescribing
• Measuring mutexes, spinlocks and how bad the Linux scheduler is
• Ask HN: How do I choose the right resource to learn CS fundamentals?