Revert "Env variables for python downloads" (#6431)

This reverts commit bbd9adaa40 from #6416
— the Python download variable is not aligned with the setting.

crates/uv-cli/src/lib.rs

@@ -115,30 +115,16 @@ pub struct GlobalArgs {
         global = true,
         long,
         help_heading = "Python options",
-        display_order = 700,
+        display_order = 700
-        env = "UV_PYTHON_PREFERENCE"
     )]
     pub python_preference: Option<PythonPreference>,
 
     /// Allow automatically downloading Python when required.
-    #[arg(
+    #[arg(global = true, long, help_heading = "Python options", hide = true)]
-        global = true,
-        long,
-        help_heading = "Python options",
-        hide = true,
-        value_parser = clap::builder::BoolishValueParser::new(),
-        env = "UV_ALLOW_PYTHON_DOWNLOADS"
-    )]
     pub allow_python_downloads: bool,
 
     /// Disable automatic downloads of Python.
-    #[arg(
+    #[arg(global = true, long, help_heading = "Python options")]
-        global = true,
-        long,
-        help_heading = "Python options",
-        value_parser = clap::builder::BoolishValueParser::new(),
-        env = "UV_NO_PYTHON_DOWNLOADS"
-    )]
     pub no_python_downloads: bool,
 
     /// Deprecated version of [`Self::python_downloads`].

crates/uv/tests/help.rs

@@ -39,10 +39,10 @@ fn help() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output
@@ -101,10 +101,10 @@ fn help_flag() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output
@@ -162,10 +162,10 @@ fn help_short_flag() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output
@@ -275,8 +275,6 @@ fn help_subcommand() {
               Python installations if a uv-managed Python is not installed. This option allows
               prioritizing or ignoring system Python installations.
 
-              [env: UV_PYTHON_PREFERENCE=]
-
               Possible values:
               - only-managed: Only use managed Python installations; never use system Python
                 installations
@@ -288,8 +286,6 @@ fn help_subcommand() {
           --no-python-downloads
               Disable automatic downloads of Python
 
-              [env: UV_NO_PYTHON_DOWNLOADS=]
-
     Global options:
       -q, --quiet
               Do not print any output
@@ -426,8 +422,6 @@ fn help_subsubcommand() {
               Python installations if a uv-managed Python is not installed. This option allows
               prioritizing or ignoring system Python installations.
 
-              [env: UV_PYTHON_PREFERENCE=]
-
               Possible values:
               - only-managed: Only use managed Python installations; never use system Python
                 installations
@@ -439,8 +433,6 @@ fn help_subsubcommand() {
           --no-python-downloads
               Disable automatic downloads of Python
 
-              [env: UV_NO_PYTHON_DOWNLOADS=]
-
     Global options:
       -q, --quiet
               Do not print any output
@@ -539,10 +531,10 @@ fn help_flag_subcommand() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output
@@ -591,10 +583,10 @@ fn help_flag_subsubcommand() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output
@@ -723,10 +715,10 @@ fn help_with_global_option() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output
@@ -822,10 +814,10 @@ fn help_with_no_pager() {
 
     Python options:
           --python-preference <PYTHON_PREFERENCE>
-              Whether to prefer uv-managed or system Python installations [env: UV_PYTHON_PREFERENCE=]
+              Whether to prefer uv-managed or system Python installations [possible values:
-              [possible values: only-managed, managed, system, only-system]
+              only-managed, managed, system, only-system]
           --no-python-downloads
-              Disable automatic downloads of Python [env: UV_NO_PYTHON_DOWNLOADS=]
+              Disable automatic downloads of Python
 
     Global options:
       -q, --quiet                      Do not print any output

docs/configuration/environment.md

@@ -69,10 +69,6 @@ In addition, uv respects the following environment variables:
   packages.
 - `UV_TOOL_DIR`: Used to specify the directory where uv will store managed tools.
 - `UV_TOOL_BIN_DIR`: Used to specify the "bin" directory where uv will install tool executables.
-- `UV_NO_PYTHON_DOWNLOADS`: Disable automatic downloads of Python.
-- `UV_ALLOW_PYTHON_DOWNLOADS`: Allow automatically downloading Python when required.
-- `UV_PYTHON_PREFERENCE`: Whether to prefer using Python installations that are already present on
-  the system, or those that are downloaded and installed by uv.
 - `UV_PYTHON_INSTALL_DIR`: Used to specify the directory where uv will store managed Python
   installations.
 - `UV_PYTHON_INSTALL_MIRROR`: Managed Python installations are downloaded from