Add --install-dir arg to uv python install and uninstall (#7920)

## Summary

This PR adds `--install-dir` argument for the following commands:
- `uv python install`
- `uv python uninstall`

The `UV_PYTHON_INSTALL_DIR` env variable can be used to set it
(previously it was also used internally).

Any more commands we would want to add this to? 

## Test Plan

For now just manual test (works on my machine hehe)

```
❯ ./target/debug/uv python install --install-dir /tmp/pythons 3.8.12
Searching for Python versions matching: Python 3.8.12
Installed Python 3.8.12 in 4.31s
 + cpython-3.8.12-linux-x86_64-gnu
❯ /tmp/pythons/cpython-3.8.12-linux-x86_64-gnu/bin/python --help
usage: /tmp/pythons/cpython-3.8.12-linux-x86_64-gnu/bin/python [option] ... [-c cmd | -m mod | file | -] [arg] ...
```

Open to add some tests after the initial feedback.

---------

Co-authored-by: Zanie Blue <contact@zanie.dev>

crates/uv-cli/src/lib.rs

@@ -4250,6 +4250,16 @@ pub struct PythonDirArgs {
 #[derive(Args)]
 #[allow(clippy::struct_excessive_bools)]
 pub struct PythonInstallArgs {
+    /// The directory to store the Python installation in.
+    ///
+    /// If provided, `UV_PYTHON_INSTALL_DIR` will need to be set for subsequent operations for
+    /// uv to discover the Python installation.
+    ///
+    /// See `uv python dir` to view the current Python installation directory. Defaults to
+    /// `~/.local/share/uv/python`.
+    #[arg(long, short, env = "UV_PYTHON_INSTALL_DIR")]
+    pub install_dir: Option<PathBuf>,
+
     /// The Python version(s) to install.
     ///
     /// If not provided, the requested Python version(s) will be read from the
@@ -4310,6 +4320,10 @@ pub struct PythonInstallArgs {
 #[derive(Args)]
 #[allow(clippy::struct_excessive_bools)]
 pub struct PythonUninstallArgs {
+    /// The directory where the Python was installed.
+    #[arg(long, short, env = "UV_PYTHON_INSTALL_DIR")]
+    pub install_dir: Option<PathBuf>,
+
     /// The Python version(s) to uninstall.
     ///
     /// See `uv help python` to view supported request formats.

crates/uv-python/src/discovery.rs

@@ -302,7 +302,7 @@ fn python_executables_from_installed<'a>(
     preference: PythonPreference,
 ) -> Box<dyn Iterator<Item = Result<(PythonSource, PathBuf), Error>> + 'a> {
     let from_managed_installations = std::iter::once_with(move || {
-        ManagedPythonInstallations::from_settings()
+        ManagedPythonInstallations::from_settings(None)
             .map_err(Error::from)
             .and_then(|installed_installations| {
                 debug!(

crates/uv-python/src/installation.rs

@@ -135,7 +135,7 @@ impl PythonInstallation {
         python_install_mirror: Option<&str>,
         pypy_install_mirror: Option<&str>,
     ) -> Result<Self, Error> {
-        let installations = ManagedPythonInstallations::from_settings()?.init()?;
+        let installations = ManagedPythonInstallations::from_settings(None)?.init()?;
         let installations_dir = installations.root();
         let scratch_dir = installations.scratch();
         let _lock = installations.lock().await?;

crates/uv-python/src/managed.rs

@@ -107,11 +107,15 @@ impl ManagedPythonInstallations {
     }
 
     /// Prefer, in order:
-    /// 1. The specific Python directory specified by the user, i.e., `UV_PYTHON_INSTALL_DIR`
-    /// 2. A directory in the system-appropriate user-level data directory, e.g., `~/.local/uv/python`
-    /// 3. A directory in the local data directory, e.g., `./.uv/python`
-    pub fn from_settings() -> Result<Self, Error> {
-        if let Some(install_dir) = std::env::var_os(EnvVars::UV_PYTHON_INSTALL_DIR) {
+    ///
+    /// 1. The specific Python directory passed via the `install_dir` argument.
+    /// 2. The specific Python directory specified with the `UV_PYTHON_INSTALL_DIR` environment variable.
+    /// 3. A directory in the system-appropriate user-level data directory, e.g., `~/.local/uv/python`.
+    /// 4. A directory in the local data directory, e.g., `./.uv/python`.
+    pub fn from_settings(install_dir: Option<PathBuf>) -> Result<Self, Error> {
+        if let Some(install_dir) = install_dir {
+            Ok(Self::from_path(install_dir))
+        } else if let Some(install_dir) = std::env::var_os(EnvVars::UV_PYTHON_INSTALL_DIR) {
             Ok(Self::from_path(install_dir))
         } else {
             Ok(Self::from_path(
@@ -227,7 +231,7 @@ impl ManagedPythonInstallations {
     ) -> Result<impl DoubleEndedIterator<Item = ManagedPythonInstallation>, Error> {
         let platform_key = platform_key_from_env()?;
 
-        let iter = ManagedPythonInstallations::from_settings()?
+        let iter = ManagedPythonInstallations::from_settings(None)?
             .find_all()?
             .filter(move |installation| {
                 installation

crates/uv/src/commands/python/dir.rs

@@ -11,7 +11,7 @@ pub(crate) fn dir(bin: bool) -> anyhow::Result<()> {
         let bin = python_executable_dir()?;
         println!("{}", bin.simplified_display().cyan());
     } else {
-        let installed_toolchains = ManagedPythonInstallations::from_settings()
+        let installed_toolchains = ManagedPythonInstallations::from_settings(None)
             .context("Failed to initialize toolchain settings")?;
         println!(
             "{}",

crates/uv/src/commands/python/install.rs

@@ -121,6 +121,7 @@ impl Changelog {
 #[allow(clippy::fn_params_excessive_bools)]
 pub(crate) async fn install(
     project_dir: &Path,
+    install_dir: Option<PathBuf>,
     targets: Vec<String>,
     reinstall: bool,
     force: bool,
@@ -178,7 +179,7 @@ pub(crate) async fn install(
     };
 
     // Read the existing installations, lock the directory for the duration
-    let installations = ManagedPythonInstallations::from_settings()?.init()?;
+    let installations = ManagedPythonInstallations::from_settings(install_dir)?.init()?;
     let installations_dir = installations.root();
     let scratch_dir = installations.scratch();
     let _lock = installations.lock().await?;

crates/uv/src/commands/python/uninstall.rs

@@ -22,12 +22,14 @@ use crate::printer::Printer;
 
 /// Uninstall managed Python versions.
 pub(crate) async fn uninstall(
+    install_dir: Option<PathBuf>,
     targets: Vec<String>,
     all: bool,
 
     printer: Printer,
 ) -> Result<ExitStatus> {
-    let installations = ManagedPythonInstallations::from_settings()?.init()?;
+    let installations = ManagedPythonInstallations::from_settings(install_dir)?.init()?;
+
     let _lock = installations.lock().await?;
 
     // Perform the uninstallation.

crates/uv/src/lib.rs

@@ -1104,6 +1104,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
 
             commands::python_install(
                 &project_dir,
+                args.install_dir,
                 args.targets,
                 args.reinstall,
                 args.force,
@@ -1127,7 +1128,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
             let args = settings::PythonUninstallSettings::resolve(args, filesystem);
             show_settings!(args);
 
-            commands::python_uninstall(args.targets, args.all, printer).await
+            commands::python_uninstall(args.install_dir, args.targets, args.all, printer).await
         }
         Commands::Python(PythonNamespace {
             command: PythonCommand::Find(args),

crates/uv/src/settings.rs

@@ -760,6 +760,7 @@ impl PythonDirSettings {
 #[allow(clippy::struct_excessive_bools)]
 #[derive(Debug, Clone)]
 pub(crate) struct PythonInstallSettings {
+    pub(crate) install_dir: Option<PathBuf>,
     pub(crate) targets: Vec<String>,
     pub(crate) reinstall: bool,
     pub(crate) force: bool,
@@ -784,6 +785,7 @@ impl PythonInstallSettings {
         let pypy_mirror = args.pypy_mirror.or(pypy_mirror);
 
         let PythonInstallArgs {
+            install_dir,
             targets,
             reinstall,
             force,
@@ -793,6 +795,7 @@ impl PythonInstallSettings {
         } = args;
 
         Self {
+            install_dir,
             targets,
             reinstall,
             force,
@@ -807,6 +810,7 @@ impl PythonInstallSettings {
 #[allow(clippy::struct_excessive_bools)]
 #[derive(Debug, Clone)]
 pub(crate) struct PythonUninstallSettings {
+    pub(crate) install_dir: Option<PathBuf>,
     pub(crate) targets: Vec<String>,
     pub(crate) all: bool,
 }
@@ -818,9 +822,17 @@ impl PythonUninstallSettings {
         args: PythonUninstallArgs,
         _filesystem: Option<FilesystemOptions>,
     ) -> Self {
-        let PythonUninstallArgs { targets, all } = args;
+        let PythonUninstallArgs {
+            install_dir,
+            targets,
+            all,
+        } = args;
 
-        Self { targets, all }
+        Self {
+            install_dir,
+            targets,
+            all,
+        }
     }
 }
 

crates/uv/tests/it/common/mod.rs

@@ -1075,7 +1075,7 @@ pub fn venv_to_interpreter(venv: &Path) -> PathBuf {
 
 /// Get the path to the python interpreter for a specific python version.
 pub fn get_python(version: &PythonVersion) -> PathBuf {
-    ManagedPythonInstallations::from_settings()
+    ManagedPythonInstallations::from_settings(None)
         .map(|installed_pythons| {
             installed_pythons
                 .find_version(version)

crates/uv/tests/it/help.rs

@@ -450,7 +450,7 @@ fn help_subcommand() {
 fn help_subsubcommand() {
     let context = TestContext::new_with_versions(&[]);
 
-    uv_snapshot!(context.filters(), context.help().arg("python").arg("install"), @r##"
+    uv_snapshot!(context.filters(), context.help().arg("python").arg("install"), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -483,6 +483,17 @@ fn help_subsubcommand() {
               See `uv help python` to view supported request formats.
 
     Options:
+      -i, --install-dir <INSTALL_DIR>
+              The directory to store the Python installation in.
+              
+              If provided, `UV_PYTHON_INSTALL_DIR` will need to be set for subsequent operations for uv
+              to discover the Python installation.
+              
+              See `uv python dir` to view the current Python installation directory. Defaults to
+              `~/.local/share/uv/python`.
+              
+              [env: UV_PYTHON_INSTALL_DIR=]
+
           --mirror <MIRROR>
               Set the URL to use as the source for downloading Python installations.
               
@@ -673,7 +684,7 @@ fn help_subsubcommand() {
 
 
     ----- stderr -----
-    "##);
+    "###);
 }
 
 #[test]
@@ -759,6 +770,8 @@ fn help_flag_subsubcommand() {
       [TARGETS]...  The Python version(s) to install
 
     Options:
+      -i, --install-dir <INSTALL_DIR>  The directory to store the Python installation in [env:
+                                       UV_PYTHON_INSTALL_DIR=]
           --mirror <MIRROR>            Set the URL to use as the source for downloading Python
                                        installations [env: UV_PYTHON_INSTALL_MIRROR=]
           --pypy-mirror <PYPY_MIRROR>  Set the URL to use as the source for downloading PyPy

crates/uv/tests/it/python_install.rs

@@ -74,7 +74,7 @@ fn python_install() {
     error: the following required arguments were not provided:
       <TARGETS>...
 
-    Usage: uv python uninstall <TARGETS>...
+    Usage: uv python uninstall --install-dir <INSTALL_DIR> <TARGETS>...
 
     For more information, try '--help'.
     "###);
@@ -209,7 +209,7 @@ fn python_install_preview() {
     error: the following required arguments were not provided:
       <TARGETS>...
 
-    Usage: uv python uninstall <TARGETS>...
+    Usage: uv python uninstall --install-dir <INSTALL_DIR> <TARGETS>...
 
     For more information, try '--help'.
     "###);

docs/reference/cli.md

@@ -4553,6 +4553,13 @@ uv python install [OPTIONS] [TARGETS]...
 
 </dd><dt><code>--help</code>, <code>-h</code></dt><dd><p>Display the concise help for this command</p>
 
+</dd><dt><code>--install-dir</code>, <code>-i</code> <i>install-dir</i></dt><dd><p>The directory to store the Python installation in.</p>
+
+<p>If provided, <code>UV_PYTHON_INSTALL_DIR</code> will need to be set for subsequent operations for uv to discover the Python installation.</p>
+
+<p>See <code>uv python dir</code> to view the current Python installation directory. Defaults to <code>~/.local/share/uv/python</code>.</p>
+
+<p>May also be set with the <code>UV_PYTHON_INSTALL_DIR</code> environment variable.</p>
 </dd><dt><code>--mirror</code> <i>mirror</i></dt><dd><p>Set the URL to use as the source for downloading Python installations.</p>
 
 <p>The provided URL will replace <code>https://github.com/indygreg/python-build-standalone/releases/download</code> in, e.g., <code>https://github.com/indygreg/python-build-standalone/releases/download/20240713/cpython-3.12.4%2B20240713-aarch64-apple-darwin-install_only.tar.gz</code>.</p>
@@ -5114,6 +5121,9 @@ uv python uninstall [OPTIONS] <TARGETS>...
 
 </dd><dt><code>--help</code>, <code>-h</code></dt><dd><p>Display the concise help for this command</p>
 
+</dd><dt><code>--install-dir</code>, <code>-i</code> <i>install-dir</i></dt><dd><p>The directory where the Python was installed</p>
+
+<p>May also be set with the <code>UV_PYTHON_INSTALL_DIR</code> environment variable.</p>
 </dd><dt><code>--native-tls</code></dt><dd><p>Whether to load TLS certificates from the platform&#8217;s native certificate store.</p>
 
 <p>By default, uv loads certificates from the bundled <code>webpki-roots</code> crate. The <code>webpki-roots</code> are a reliable set of trust roots from Mozilla, and including them in uv improves portability and performance (especially on macOS).</p>