Rust developers upgrade to newer versions of Rust _vastly_ faster than Python developers do.
As of yesterday:
11% of downloads on PyPI were for Python versions 3.12 or newer, released in October 2023.
97% of package downloads on crates.io were for Rust 1.75 or later, released in December 2023.
From my experience, there's a rational reason for this difference: major Python vresion upgrades usually aren't _hard_, but they do require some tweaking. So there's always lag. Meanwhile, Rust upgrades are a non-event, with no changes to user code needed. And insofar as Rust wants to introduce breaking changes, the edition mechanism means it's opt-in rather than being forced on you when you upgrade.
UPDATE: As someone implied in their replies, this is somewhat misleading insofar as it includes lots of open source projects that are testing in CI against old Python versions. Even so, if open source project CI dominated download numbers, I would expect something like 40% of downloads to be for Python 3.12 or later, since most projects are likely supporting 3.9-3.13 at the moment.
Data sources:
- https://pypistats.org/packages/__all__
- https://lib.rs/stats#rustc