What's new in pip 26.1 - lockfiles and dependency cooldowns!
The latest release of pip, version 26.1, introduces several enhancements including lockfiles and dependency cooldowns. This version has dropped support for Python 3.9, which reached its end of life in October. Users can now utilize the new features to manage dependencies more effectively.
- ▪Pip 26.1 drops support for Python 3.9 due to its end of life status.
- ▪The new lockfiles feature allows users to install dependencies and generate a pylock.toml file.
- ▪Dependency cooldowns can now be managed using the --uploaded-prior-to option.
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| Original publisher | Simon Willison |
| Canonical URL | https://simonwillison.net/2026/Apr/28/pip-261/#atom-everything |
| Publication time | 2026-04-28T05:23:05+00:00 |
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Opening excerpt (first ~120 words) tap to expand
What's new in pip 26.1 - lockfiles and dependency cooldowns! (via) Richard Si describes an excellent set of upgrades to Python's default pip tool for installing dependencies. This version drops support for Python 3.9 - fair enough, since it's been EOL since October. macOS still ships with python3 as a default Python 3.9, so I tried out the new Python version against Python 3.14 like this: uv python install 3.14 mkdir /tmp/experiment cd /tmp/experiment python3.14 -m venv venv source venv/bin/activate pip install -U pip pip --version This confirmed I had pip 26.1 - then I tried out the new lock files: pip lock datasette llm This installs Datasette and LLM and all of their dependencies and writes the whole lot to a 519 line pylock.toml file - here's the result.
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