Why it took 4 years to get a lock files specification

Work started on a lock file specification for Python in earnest on 2021-01-31 and culminated in PEP 751 being accepted on 2025-03-31! While it's great that a conclusion was reached, why did it take 4 years to go from idea to acceptance? Because Python packaging is, in a word, hard.

The flexibility that Python packaging provides has led to over 600,000 projects on PyPI and Python becoming the glue language of the internet, but at the cost of some complexity and not having "one tool to rule them all". This talk will cover why Python packaging is hard and how that played into creating a lock file specification. The history of the spec and what it provides will also be covered.