> NOTE: The PRs that were merged into this feature branch have all been
independently reviewed. But it's also useful to see all of the changes
in their final form. I've added comments to significant changes
throughout the PR to aid discussion.
This PR introduces transparent Python version upgrades to uv, allowing
for a smoother experience when upgrading to new patch versions.
Previously, upgrading Python patch versions required manual updates to
each virtual environment. Now, virtual environments can transparently
upgrade to newer patch versions.
Due to significant changes in how uv installs and executes managed
Python executables, this functionality is initially available behind a
`--preview` flag. Once an installation has been made upgradeable through
`--preview`, subsequent operations (like `uv venv -p 3.10` or patch
upgrades) will work without requiring the flag again. This is
accomplished by checking for the existence of a minor version symlink
directory (or junction on Windows).
### Features
* New `uv python upgrade` command to upgrade installed Python versions
to the latest available patch release:
```
# Upgrade specific minor version
uv python upgrade 3.12 --preview
# Upgrade all installed minor versions
uv python upgrade --preview
```
* Transparent upgrades also occur when installing newer patch versions:
```
uv python install 3.10.8 --preview
# Automatically upgrades existing 3.10 environments
uv python install 3.10.18
```
* Support for transparently upgradeable Python `bin` installations via
`--preview` flag
```
uv python install 3.13 --preview
# Automatically upgrades the `bin` installation if there is a newer patch version available
uv python upgrade 3.13 --preview
```
* Virtual environments can still be tied to a patch version if desired
(ignoring patch upgrades):
```
uv venv -p 3.10.8
```
### Implementation
Transparent upgrades are implemented using:
* Minor version symlink directories (Unix) or junctions (Windows)
* On Windows, trampolines simulate paths with junctions
* Symlink directory naming follows Python build standalone format: e.g.,
`cpython-3.10-macos-aarch64-none`
* Upgrades are scoped to the minor version key (as represented in the
naming format: implementation-minor version+variant-os-arch-libc)
* If the context does not provide a patch version request and the
interpreter is from a managed CPython installation, the `Interpreter`
used by `uv python run` will use the full symlink directory executable
path when available, enabling transparently upgradeable environments
created with the `venv` module (`uv run python -m venv`)
New types:
* `PythonMinorVersionLink`: in a sense, the core type for this PR, this
is a representation of a minor version symlink directory (or junction on
Windows) that points to the highest installed managed CPython patch
version for a minor version key.
* `PythonInstallationMinorVersionKey`: provides a view into a
`PythonInstallationKey` that excludes the patch and prerelease. This is
used for grouping installations by minor version key (e.g., to find the
highest available patch installation for that minor version key) and for
minor version directory naming.
### Compatibility
* Supports virtual environments created with:
* `uv venv`
* `uv run python -m venv` (using managed Python that was installed or
upgraded with `--preview`)
* Virtual environments created within these environments
* Existing virtual environments from before these changes continue to
work but aren't transparently upgradeable without being recreated
* Supports both standard Python (`python3.10`) and freethreaded Python
(`python3.10t`)
* Support for transparently upgrades is currently only available for
managed CPython installations
Closes#7287Closes#7325Closes#7892Closes#9031Closes#12977
---------
Co-authored-by: Zanie Blue <contact@zanie.dev>
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## Summary
I follow the advices from the IDE spell checker and grammar checker, fix
some typos, and improve the docs.
Extends https://github.com/astral-sh/uv/pull/13841 — I'll drop that
commit later after that pull request merges but it's small.
I find the split into a "Configuration" section awkward and don't think
it's helping us. Everything moved into the "Concepts" section, except
the "Environment variables" page which definitely belongs in the
reference and the "Installer" page which is fairly niche and seems
better in the reference.
Before / After
<img
src="https://github.com/user-attachments/assets/80d8304b-17da-4900-a5f4-c3ccac96fcc5"
width="400">
Allows `uv python list <request>` to filter the installed list. I often
want this and it's not hard to add.
I tested the remote download filtering locally (#12381 is needed for
snapshot tests)
```
❯ cargo run -q -- python list --all-versions 3.13
cpython-3.13.2-macos-aarch64-none <download available>
cpython-3.13.1-macos-aarch64-none /opt/homebrew/opt/python@3.13/bin/python3.13 -> ../Frameworks/Python.framework/Versions/3.13/bin/python3.13
cpython-3.13.1-macos-aarch64-none <download available>
cpython-3.13.0-macos-aarch64-none /Users/zb/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/bin/python3.13
❯ cargo run -q -- python list --all-versions 3.13 --only-installed
cpython-3.13.1-macos-aarch64-none /opt/homebrew/opt/python@3.13/bin/python3.13 -> ../Frameworks/Python.framework/Versions/3.13/bin/python3.13
cpython-3.13.0-macos-aarch64-none /Users/zb/.local/share/uv/python/cpython-3.13.0-macos-aarch64-none/bin/python3.13
```
Currently, for users to specify at the command line whether to use
uv-managed or system Python interpreters, they use the
`--python-preference` parameter, which takes four possible values. This
is more complex than necessary since the normal case is to either say
"only managed" or "not managed". This PR hides the old
`--python-preference` parameter from help and documentation and adds two
new flags: `--managed-python` and `--no-managed-python` to capture the
"only managed" and "not managed" cases.
I have successfully tested this locally but currently cannot add
snapshot tests because of problems with distinguishing managed vs.
system interpreters in CI (and non-determinism when run on different
developers' machines). The `--python-preference` test in
`tool-install.rs` is currently ignored for this reason. See #5144 and
#7473.
---------
Co-authored-by: Zanie Blue <contact@zanie.dev>
These changes add support for
```
uv python pin 3.12 --global
```
This adds the specified version to a `.python-version` file in the
user-level config directory. uv will now use the user-level version as a
fallback if no version is found in the project directory or its
ancestors.
Closes#4972
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## Summary
The command `uv python find >=3.11` doesn't work . The version should be
quoted otherwise the terminal interprets the `>` and pipes output to a
file named `=3.11`. I've used single quotes as used on line 90 of this
file.
## Test Plan
Locally
Similar to our semantics for packages with pre-release versions.
We will not use prerelease versions unless there are only prerelease
versions available, a specific version is requested,
or the prerelease version is found in a reasonable source (active
environment, explicit path, etc. but not `PATH`).
For example, `uv python install 3.13 && uv run python --version` will no
longer use `3.13.0rc2` unless that is the only Python version available,
`--python 3.13` is used, or that's the Python version that is present in
`.venv`.
## Summary
Closes https://github.com/astral-sh/uv/issues/7027
* When displaying the file structure of a uv-managed project show the
`.python-version` file which is now created by default.
* Mention the purpose of the `.python-version` file in `Guides/Working
on projects/Project structure`
* In `Concepts/Python versions/Project python versions`, changed
sentence about `.python-version` file to reflect the fact it is included
by default so is likely to be present.
Our current strategy of parsing the output of `py --list-paths` to get
the installed python versions on windows is brittle (#6524, missing
`py`, etc.) and it's slow (10ms last time i measured).
Instead, we should behave spec-compliant and read the python versions
from the registry following PEP 514.
It's not fully clear which errors we should ignore and which ones we
need to raise.
We're using the official rust-for-windows crates for accessing the
registry.
Fixes#1521Fixes#6524
As described in #4242, we're currently incorrectly downloading glibc
python-build-standalone on musl target, but we also can't fix this by
using musl python-build-standalone on musl targets since the musl builds
are effectively broken.
We reintroduce the libc detection previously removed in #2381, using it
to detect which libc is the current one before we have a python
interpreter. I changed the strategy a big to support an empty `PATH`
which we use in the tests.
For simplicity, i've decided to just filter out the musl
python-build-standalone archives from the list of available archive,
given this is temporary. This means we show the same error message as if
we don't have a build for the platform. We could also add a dedicated
error message for musl.
Fixes#4242
## Test Plan
Tested manually.
On my ubuntu host, python downloads continue to pass:
```
target/x86_64-unknown-linux-musl/debug/uv python install
```
On alpine, we fail:
```
$ docker run -it --rm -v .:/io alpine /io/target/x86_64-unknown-linux-musl/debug/uv python install
Searching for Python installations
error: No download found for request: cpython-any-linux-x86_64-musl
```
The loose consensus is that "fetch" doesn't have much meaning and that a
boolean flag makes more sense from the command line.
1. Adds `--allow-python-downloads` (hidden, default) and
`--no-python-downloads` to the CLI to quickly enable or disable
downloads
2. Deprecates `--python-fetch` in favor of the options from (1)
3. Removes `python-fetch` in favor of a `python-downloads` setting
5. Adds a `never` variant to the enum, allowing even explicit installs
to be disabled via the configuration file
## Test plan
I tested this with various `pyproject.toml`-level settings and `uv venv
--preview --python 3.12.2` and `uv python install 3.12.2` with and
without the new CLI flags.
To enforce the 100 character line limit in markdown files introduced in
https://github.com/astral-sh/uv/pull/5635, and to automate the
formatting of markdown files, i've added prettier and formatted our
markdown files with it.
I've excluded the changelog and the generated references documentation
from this for having too many changes, but we can also include them.
I'm not particular on which style we use. My main motivations are
(major) not having to reflow markdown files myself anymore and (minor)
consistence between all markdown files. I've chosen prettier for similar
reason as we chose black, it's a single good style that's automated and
shared in the community. I do prefer prettier's style of not breaking
inside of a link name though.
This PR is in two parts, the first adds prettier to CI and documents
using it, while the second actually formats the docs. When merge
conflicts arise, we can drop the last commit and regenerate it with `npx
prettier --prose-wrap always --write BENCHMARKS.md CONTRIBUTING.md
README.md STYLE.md docs/*.md docs/concepts/**/*.md docs/guides/**/*.md
docs/pip/**/*.md`.
---------
Co-authored-by: Zanie Blue <contact@zanie.dev>
