uv/docs/guides/install-python.md
FishAlchemist 9736868908
Add meta titles to documents in guides, excluding integration documents. (#10539)
## Summary
Add meta titles to documents in guides, excluding integration documents.
<!-- What's the purpose of the change? What does it do, and why? -->

## Test Plan
``uvx --with-requirements docs/requirements.txt -- mkdocs build --strict
-f mkdocs.public.yml``
<details>
 <summary>Build Result</summary>

* ``guides/install-python``
```html
...
<meta name="description" content="Guide to install specific Python versions, manage existing installations, and automate downloads with uv.">
...
<title>Install and Manage Python | uv</title>
...
```
* ``guides/projects``
```html
...
<meta name="description" content="Guide to create, manage, and build Python projects with uv, including dependencies and distributions.">
...
<title>Working on projects | uv</title>
...
```
* ``guides/publish``
```html
...
<meta name="description" content="Guide to build and publish Python packages using uv">
...
<title>Publishing a package | uv</title>
...
```
* ``guides/scripts``
```html
...
<meta name="description" content="Run Python scripts quickly and manage dependencies efficiently using uv. Learn about inline metadata and more.">
...
<title>Run Scripts | uv</title>
...
```
* ``guides/tools``
```html
...
<meta name="description" content="Guide to run, install, and upgrade Python tools using uv.">
...
<title>Using tools | uv</title>
...
```
</details>

---------

Co-authored-by: Charles Tapley Hoyt <cthoyt@gmail.com>
Co-authored-by: Zanie Blue <contact@zanie.dev>
2025-01-15 14:12:55 -06:00

126 lines
4.4 KiB
Markdown

---
title: Installing and managing Python
description:
A guide to using uv to install Python, including requesting specific versions, automatic
installation, viewing installed versions, and more.
---
# Installing Python
If Python is already installed on your system, uv will
[detect and use](#using-an-existing-python-installation) it without configuration. However, uv can
also install and manage Python versions for you.
!!! tip
uv will [automatically fetch Python versions](#automatic-python-downloads) as needed — you don't need to install Python to get started.
<!-- TODO(zanieb): I don't love this heading. -->
## Getting started
To install the latest Python version:
```console
$ uv python install
```
This will install a uv-managed Python version even if there is already a Python installation on your
system. If you've previously installed Python with uv, a new version will not be installed.
!!! note
Python does not publish official distributable binaries. As such, uv uses distributions from Astral [`python-build-standalone`](https://github.com/astral-sh/python-build-standalone) project. See the [Python distributions](../concepts/python-versions.md#managed-python-distributions) documentation for more details.
Once Python is installed, it will be used by `uv` commands automatically.
!!! important
When Python is installed by uv, it will not be available globally (i.e. via the `python` command).
Support for this feature is in _preview_. See [Installing Python executables](../concepts/python-versions.md#installing-python-executables)
for details.
You can still use
[`uv run`](../guides/scripts.md#using-different-python-versions) or
[create and activate a virtual environment](../pip/environments.md) to use `python` directly.
## Installing a specific version
To install a specific Python version:
```console
$ uv python install 3.12
```
To install multiple Python versions:
```console
$ uv python install 3.11 3.12
```
To install an alternative Python implementation, e.g. PyPy:
```console
$ uv python install pypy@3.10
```
See the [`python install`](../concepts/python-versions.md#installing-a-python-version) documentation
for more details.
## Viewing Python installations
To view available and installed Python versions:
```console
$ uv python list
```
See the [`python list`](../concepts/python-versions.md#viewing-available-python-versions)
documentation for more details.
<!--TODO(zanieb): The above should probably link to a CLI reference and that content should be moved out of that file -->
## Automatic Python downloads
Note that Python does not need to be explicitly installed to use uv. By default, uv will
automatically download Python versions when they are required. For example, the following would
download Python 3.12 if it was not installed:
```console
$ uv run --python 3.12 python -c "print('hello world')"
```
Even if a specific Python version is not requested, uv will download the latest version on demand.
For example, the following will create a new virtual environment and download a managed Python
version if Python is not found:
```console
$ uv venv
```
!!! tip
Automatic Python downloads can be [easily disabled](../concepts/python-versions.md#disabling-automatic-python-downloads) if you want more control over when Python is downloaded.
<!-- TODO(zanieb): Restore when Python shim management is added
Note that when an automatic Python installation occurs, the `python` command will not be added to the shell. Use `uv python install-shim` to ensure the `python` shim is installed.
-->
## Using an existing Python installation
uv will use existing Python installations if present on your system. There is no configuration
necessary for this behavior: uv will use the system Python if it satisfies the requirements of the
command invocation. See the
[Python discovery](../concepts/python-versions.md#discovery-of-python-versions) documentation for
details.
To force uv to use the system Python, provide the `--python-preference only-system` option. See the
[Python version preference](../concepts/python-versions.md#adjusting-python-version-preferences)
documentation for more details.
## Next steps
To learn more about `uv python`, see the [Python version concept](../concepts/python-versions.md)
page and the [command reference](../reference/cli.md#uv-python).
Or, read on to learn how to [run scripts](./scripts.md) and invoke Python with uv.