feat(python): pipx support

see #50
closes #48

README.md

@@ -176,6 +176,7 @@ disabled_backends: []  # backends that pacdef should not manage, e.g. ["python"]
 
 warn_not_symlinks: true  # warn if a group file is not a symlink
 flatpak_systemwide: true  # whether flatpak packages should be installed system-wide or per user
+pip_binary: pip # choose whether to use pipx instead of pip for python package management [See [Pitfalls while using pipx](#pitfalls-while-using-pipx)]
 ```
 
 
@@ -219,3 +220,6 @@ Pacdef is supported by [topgrade](https://github.com/topgrade-rs/topgrade).
 MSRV is 1.70.0 due to dependencies that require this specific version. Development is conducted against the latest stable version.
 
 
+### Pitfalls while using pipx
+
+Some packages like [mdformat-myst](https://github.com/executablebooks/mdformat-myst) do not provide an executable themselves but rather act as a plugin to their dependency, which is mdformat in this case. Please install such packages explicitly by running `pipx install <package-name> --include-deps`.

crates/pacdef_core/src/backend/actual/python.rs

@@ -12,6 +12,7 @@ use crate::{Group, Package};
 
 #[derive(Debug, Clone)]
 pub struct Python {
+    pub(crate) binary: String,
     pub(crate) packages: HashSet<Package>,
 }
 
@@ -26,19 +27,30 @@ const SWITCHES_REMOVE: Switches = &["uninstall"];
 
 const SUPPORTS_AS_DEPENDENCY: bool = false;
 
+macro_rules!  ERROR{
+    ($bin:expr) => {
+        panic!("Cannot use {} for package management in python. Please use a valid package manager like pip or pipx.", $bin)
+    };
+}
+
 impl Backend for Python {
     impl_backend_constants!();
 
-    fn get_all_installed_packages(&self) -> Result<HashSet<Package>> {
+    fn get_binary(&self) -> Text {
-        let output = run_pip_command(&["list", "--format", "json", "--user"])?;
+        let r#box = self.binary.clone().into_boxed_str();
+        Box::leak(r#box)
+    }
 
-        extract_pacdef_packages(output)
+    fn get_all_installed_packages(&self) -> Result<HashSet<Package>> {
+        let mut cmd = Command::new(self.get_binary());
+        let output = run_pip_command(&mut cmd, self.get_switches_runtime())?;
+        self.extract_packages(output)
     }
 
     fn get_explicitly_installed_packages(&self) -> Result<HashSet<Package>> {
-        let output = run_pip_command(&["list", "--format", "json", "--not-required", "--user"])?;
+        let mut cmd = Command::new(self.get_binary());
-
+        let output = run_pip_command(&mut cmd, self.get_switches_explicit())?;
-        extract_pacdef_packages(output)
+        self.extract_packages(output)
     }
 
     fn make_dependency(&self, _packages: &[Package]) -> Result<ExitStatus> {
@@ -46,8 +58,7 @@ impl Backend for Python {
     }
 }
 
-fn run_pip_command(args: &[&str]) -> Result<Value> {
+fn run_pip_command(cmd: &mut Command, args: &[&str]) -> Result<Value> {
-    let mut cmd = Command::new(BINARY);
     cmd.args(args);
     let output = String::from_utf8(cmd.output()?.stdout)?;
     let val: Value = serde_json::from_str(&output)?;
@@ -57,9 +68,33 @@ fn run_pip_command(args: &[&str]) -> Result<Value> {
 impl Python {
     pub(crate) fn new() -> Self {
         Self {
+            binary: BINARY.to_string(),
             packages: HashSet::new(),
         }
     }
+
+    fn get_switches_runtime(&self) -> Switches {
+        match self.get_binary() {
+            "pip" => &["list", "--format", "json", "--not-required", "--user"],
+            "pipx" => &["list", "--json"],
+            _ => ERROR!(self.get_binary()),
+        }
+    }
+    fn get_switches_explicit(&self) -> Switches {
+        match self.get_binary() {
+            "pip" => &["list", "--format", "json", "--user"],
+            "pipx" => &["list", "--json"],
+            _ => ERROR!(self.get_binary()),
+        }
+    }
+
+    fn extract_packages(&self, output: Value) -> Result<HashSet<Package>> {
+        match self.get_binary() {
+            "pip" => extract_pacdef_packages(output),
+            "pipx" => extract_pacdef_packages_pipx(output),
+            _ => ERROR!(self.get_binary()),
+        }
+    }
 }
 
 fn extract_pacdef_packages(value: Value) -> Result<HashSet<Package>> {
@@ -72,3 +107,13 @@ fn extract_pacdef_packages(value: Value) -> Result<HashSet<Package>> {
         .collect();
     Ok(result)
 }
+
+fn extract_pacdef_packages_pipx(value: Value) -> Result<HashSet<Package>> {
+    let result = value["venvs"]
+        .as_object()
+        .context("getting inner json object")?
+        .iter()
+        .map(|(name, _)| Package::from(name.as_str()))
+        .collect();
+    Ok(result)
+}

crates/pacdef_core/src/config.rs

@@ -24,6 +24,9 @@ pub struct Config {
     /// Backends the user does not want to use even though the binary exists.
     #[serde(default)]
     pub disabled_backends: Vec<String>,
+    /// Choose whether to use pipx instead of pip for python package management
+    #[serde(default)]
+    pub pip_binary: String,
 }
 
 fn yes() -> bool {
@@ -86,6 +89,7 @@ impl Default for Config {
             flatpak_systemwide: true,
             warn_not_symlinks: true,
             disabled_backends: vec![],
+            pip_binary: "pip".into(),
         }
     }
 }

crates/pacdef_core/src/core.rs

@@ -140,6 +140,13 @@ impl Pacdef {
         {
             flatpak.systemwide = self.config.flatpak_systemwide;
         }
+
+        if let Some(python) = backend
+            .as_any_mut()
+            .downcast_mut::<crate::backend::Python>()
+        {
+            python.binary = self.config.pip_binary.clone();
+        }
     }
 
     fn install_packages(&mut self, noconfirm: bool) -> Result<()> {