refactor the non_host part for not injecting to custom env

Author: xiacunshun

src/pipdeptree/__main__.py

@@ -8,19 +8,17 @@
 from pipdeptree._cli import get_options
 from pipdeptree._discovery import get_installed_distributions
 from pipdeptree._models import PackageDAG
-from pipdeptree._non_host import handle_non_host_target
 from pipdeptree._render import render
 from pipdeptree._validate import validate
 
 
 def main(args: Sequence[str] | None = None) -> None | int:
     """CLI - The main function called as entry point."""
     options = get_options(args)
-    result = handle_non_host_target(options)
-    if result is not None:
-        return result
 
-    pkgs = get_installed_distributions(local_only=options.local_only, user_only=options.user_only)
+    pkgs = get_installed_distributions(
+        interpreter=options.python, local_only=options.local_only, user_only=options.user_only
+    )
     tree = PackageDAG.from_pkgs(pkgs)
     is_text_output = not any([options.json, options.json_tree, options.output_format])
 

src/pipdeptree/_discovery.py

@@ -1,26 +1,45 @@
 from __future__ import annotations
 
+import ast
 import site
+import subprocess  # noqa: S404
 import sys
 from importlib.metadata import Distribution, distributions
+from pathlib import Path
 from typing import Iterable, Tuple
 
 from packaging.utils import canonicalize_name
 
 
 def get_installed_distributions(
+    interpreter: str = str(sys.executable),
     local_only: bool = False,  # noqa: FBT001, FBT002
     user_only: bool = False,  # noqa: FBT001, FBT002
 ) -> list[Distribution]:
     # See https://docs.python.org/3/library/venv.html#how-venvs-work for more details.
     in_venv = sys.prefix != sys.base_prefix
     original_dists: Iterable[Distribution] = []
+    py_path = Path(interpreter).absolute()
+    using_custom_interpreter = py_path != Path(sys.executable).absolute()
 
-    if local_only and in_venv:
+    if user_only:
+        original_dists = distributions(path=[site.getusersitepackages()])
+    elif using_custom_interpreter:
+        # We query the interpreter directly to get the `path` which is used by distributions(),
+        # so we can search the customer dists with it.
+        # If --python and --local-only are given at the same time, it means the dists only in
+        # customer's env are needed. (.e.g --system-site-packages is given when creating venv)
+        if local_only:
+            args = "import sys, site; print(site.getsitepackages([sys.prefix]))"
+        else:
+            args = "import sys; print(sys.path)"
+
+        cmd = [str(py_path), "-c", args]
+        result = subprocess.run(cmd, stdout=subprocess.PIPE, check=False)  # noqa: S603
+        original_dists = distributions(path=ast.literal_eval(result.stdout.decode("utf-8")))
+    elif local_only and in_venv:
         venv_site_packages = site.getsitepackages([sys.prefix])
         original_dists = distributions(path=venv_site_packages)
-    elif user_only:
-        original_dists = distributions(path=[site.getusersitepackages()])
     else:
         original_dists = distributions()
 

src/pipdeptree/_non_host.py

@@ -39,11 +39,3 @@ def test_custom_interpreter(
     if sys.version_info >= (3, 12):
         expected -= {"setuptools", "wheel"}
     assert found == expected, out
-
-    monkeypatch.setattr(sys, "argv", [*cmd, "--graph-output", "something"])
-    with pytest.raises(SystemExit) as context:
-        main()
-    out, err = capfd.readouterr()
-    assert context.value.code == 1
-    assert not out
-    assert err == "graphviz functionality is not supported when querying non-host python\n"