Member-only story
Python 3.15 Is Bigger Than You Think: 7 New Features Worth Using in 2026
Python 3.15 is not just another release filled with small standard-library improvements. It introduces new syntax, new built-in types, a serious profiling tool, faster execution through an upgraded JIT, and even changes something as fundamental as Python’s default text encoding. If you write Python professionally, several of these features can simplify code you are already writing today.
At the time of writing (August 2026), Python 3.15 is still a prerelease, so this is the time to test rather than blindly upgrade production systems. The feature set has already been frozen, however, making it a good moment to look at what actually matters.
First: Running Python 3.15 with uv
You do not need to replace your system Python to experiment with the release. uv makes it easy to create an isolated project and explicitly select Python 3.15.
uv init python315 --no-package
cd python315
uv python install 3.15
uv python pin 3.15
uv run python --version
uv add --dev ruffIt is also a good idea to manually update pyproject.toml so that the project explicitly declares Python 3.15 as its minimum supported version, especially when using 3.15-specific syntax such as lazy import.
