feat: respect virtualenvs.prefer-active-python on poetry new and init

src/poetry/console/commands/init.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-import sys
-
 from pathlib import Path
 from typing import TYPE_CHECKING
 from typing import Any
@@ -78,8 +76,9 @@ def handle(self) -> int:
         from poetry.core.pyproject.toml import PyProjectTOML
         from poetry.core.vcs.git import GitConfig
 
+        from poetry.config.config import Config
         from poetry.layouts import layout
-        from poetry.utils.env import SystemEnv
+        from poetry.utils.env import EnvManager
 
         project_path = Path.cwd()
 
@@ -161,10 +160,16 @@ def handle(self) -> int:
 
         python = self.option("python")
         if not python:
-            current_env = SystemEnv(Path(sys.executable))
-            default_python = "^" + ".".join(
-                str(v) for v in current_env.version_info[:2]
+            config = Config.create()
+            default_python = (
+                "^"
+                + EnvManager.get_python_version(
+                    precision=2,
+                    prefer_active_python=config.get("virtualenvs.prefer-active-python"),
+                    io=self.io,
+                ).to_string()
             )
+
             question = self.create_question(
                 f"Compatible Python versions [<comment>{default_python}</comment>]: ",
                 default=default_python,

src/poetry/console/commands/new.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-import sys
-
 from contextlib import suppress
 
 from cleo.helpers import argument
@@ -31,8 +29,9 @@ def handle(self) -> int:
 
         from poetry.core.vcs.git import GitConfig
 
+        from poetry.config.config import Config
         from poetry.layouts import layout
-        from poetry.utils.env import SystemEnv
+        from poetry.utils.env import EnvManager
 
         if self.io.input.option("directory"):
             self.line_error(
@@ -71,8 +70,17 @@ def handle(self) -> int:
             if author_email:
                 author += f" <{author_email}>"
 
-        current_env = SystemEnv(Path(sys.executable))
-        default_python = "^" + ".".join(str(v) for v in current_env.version_info[:2])
+        poetry_config = Config.create()
+        default_python = (
+            "^"
+            + EnvManager.get_python_version(
+                precision=2,
+                prefer_active_python=poetry_config.get(
+                    "virtualenvs.prefer-active-python"
+                ),
+                io=self.io,
+            ).to_string()
+        )
 
         layout_ = layout_cls(
             name,

src/poetry/utils/env.py

@@ -20,7 +20,6 @@
 from subprocess import CalledProcessError
 from typing import TYPE_CHECKING
 from typing import Any
-from typing import cast
 
 import packaging.tags
 import tomlkit
@@ -521,7 +520,8 @@ def __init__(self, poetry: Poetry, io: None | IO = None) -> None:
         self._poetry = poetry
         self._io = io or NullIO()
 
-    def _full_python_path(self, python: str) -> str:
+    @staticmethod
+    def _full_python_path(python: str) -> str:
         try:
             executable = decode(
                 subprocess.check_output(
@@ -536,23 +536,23 @@ def _full_python_path(self, python: str) -> str:
 
         return executable
 
-    def _detect_active_python(self) -> str | None:
+    @staticmethod
+    def _detect_active_python(io: None | IO = None) -> str | None:
+        io = io or NullIO()
         executable = None
 
         try:
-            self._io.write_error_line(
+            io.write_error_line(
                 (
                     "Trying to detect current active python executable as specified in"
                     " the config."
                 ),
                 verbosity=Verbosity.VERBOSE,
             )
-            executable = self._full_python_path("python")
-            self._io.write_error_line(
-                f"Found: {executable}", verbosity=Verbosity.VERBOSE
-            )
+            executable = EnvManager._full_python_path("python")
+            io.write_error_line(f"Found: {executable}", verbosity=Verbosity.VERBOSE)
         except EnvCommandError:
-            self._io.write_error_line(
+            io.write_error_line(
                 (
                     "Unable to detect the current active python executable. Falling"
                     " back to default."
@@ -561,11 +561,16 @@ def _detect_active_python(self) -> str | None:
             )
         return executable
 
-    def _get_python_version(self) -> tuple[int, int, int]:
-        version_info = tuple(sys.version_info[:3])
+    @staticmethod
+    def get_python_version(
+        precision: int = 3,
+        prefer_active_python: bool = False,
+        io: None | IO = None,
+    ) -> Version:
+        version = ".".join(str(v) for v in sys.version_info[:precision])
 
-        if self._poetry.config.get("virtualenvs.prefer-active-python"):
-            executable = self._detect_active_python()
+        if prefer_active_python:
+            executable = EnvManager._detect_active_python(io)
 
             if executable:
                 python_patch = decode(
@@ -577,9 +582,9 @@ def _get_python_version(self) -> tuple[int, int, int]:
                     ).strip()
                 )
 
-                version_info = tuple(int(v) for v in python_patch.split(".")[:3])
+                version = ".".join(str(v) for v in python_patch.split(".")[:precision])
 
-        return cast("tuple[int, int, int]", version_info)
+        return Version.parse(version)
 
     def activate(self, python: str) -> Env:
         venv_path = self._poetry.config.virtualenvs_path
@@ -692,7 +697,12 @@ def get(self, reload: bool = False) -> Env:
         if self._env is not None and not reload:
             return self._env
 
-        python_minor = ".".join([str(v) for v in self._get_python_version()[:2]])
+        prefer_active_python = self._poetry.config.get(
+            "virtualenvs.prefer-active-python"
+        )
+        python_minor = self.get_python_version(
+            precision=2, prefer_active_python=prefer_active_python, io=self._io
+        ).to_string()
 
         venv_path = self._poetry.config.virtualenvs_path
 

tests/console/commands/test_init.py

@@ -2,10 +2,12 @@
 
 import os
 import shutil
+import subprocess
 import sys
 
 from pathlib import Path
 from typing import TYPE_CHECKING
+from typing import Any
 
 import pytest
 
@@ -26,6 +28,7 @@
     from poetry.core.packages.package import Package
     from pytest_mock import MockerFixture
 
+    from poetry.config.config import Config
     from poetry.poetry import Poetry
     from tests.helpers import TestRepository
     from tests.types import FixtureDirGetter
@@ -1061,3 +1064,46 @@ def test_package_include(
         f'python = "^3.10"\n'
     )
     assert expected in tester.io.fetch_output()
+
+
+@pytest.mark.parametrize(
+    ["prefer_active", "python"],
+    [
+        (True, "1.1"),
+        (False, f"{sys.version_info[0]}.{sys.version_info[1]}"),
+    ],
+)
+def test_respect_prefer_active_on_init(
+    prefer_active: bool,
+    python: str,
+    config: Config,
+    mocker: MockerFixture,
+    tester: CommandTester,
+    source_dir: Path,
+):
+    from poetry.utils.env import GET_PYTHON_VERSION_ONELINER
+
+    orig_check_output = subprocess.check_output
+
+    def mock_check_output(cmd: str, *_: Any, **__: Any) -> str:
+        if GET_PYTHON_VERSION_ONELINER in cmd:
+            return "1.1.1"
+
+        return orig_check_output(cmd, *_, **__)
+
+    mocker.patch("subprocess.check_output", side_effect=mock_check_output)
+
+    config.config["virtualenvs"]["prefer-active-python"] = prefer_active
+    pyproject_file = source_dir / "pyproject.toml"
+
+    tester.execute(
+        "--author 'Your Name <[email protected]>' --name 'my-package'",
+        interactive=False,
+    )
+
+    expected = f"""\
+[tool.poetry.dependencies]
+python = "^{python}"
+"""
+
+    assert expected in pyproject_file.read_text()

tests/console/commands/test_new.py

@@ -1,7 +1,11 @@
 from __future__ import annotations
 
+import subprocess
+import sys
+
 from pathlib import Path
 from typing import TYPE_CHECKING
+from typing import Any
 
 import pytest
 
@@ -10,7 +14,9 @@
 
 if TYPE_CHECKING:
     from cleo.testers.command_tester import CommandTester
+    from pytest_mock import MockerFixture
 
+    from poetry.config.config import Config
     from poetry.poetry import Poetry
     from tests.types import CommandTesterFactory
 
@@ -170,3 +176,47 @@ def test_command_new_with_readme(fmt: str | None, tester: CommandTester, tmp_dir
 
     poetry = verify_project_directory(path, package, package, None)
     assert poetry.local_config.get("readme") == f"README.{fmt or 'md'}"
+
+
+@pytest.mark.parametrize(
+    ["prefer_active", "python"],
+    [
+        (True, "1.1"),
+        (False, f"{sys.version_info[0]}.{sys.version_info[1]}"),
+    ],
+)
+def test_respect_prefer_active_on_new(
+    prefer_active: bool,
+    python: str,
+    config: Config,
+    mocker: MockerFixture,
+    tester: CommandTester,
+    tmp_dir: str,
+):
+    from poetry.utils.env import GET_PYTHON_VERSION_ONELINER
+
+    orig_check_output = subprocess.check_output
+
+    def mock_check_output(cmd: str, *_: Any, **__: Any) -> str:
+        if GET_PYTHON_VERSION_ONELINER in cmd:
+            return "1.1.1"
+
+        return orig_check_output(cmd, *_, **__)
+
+    mocker.patch("subprocess.check_output", side_effect=mock_check_output)
+
+    config.config["virtualenvs"]["prefer-active-python"] = prefer_active
+
+    package = "package"
+    path = Path(tmp_dir) / package
+    options = [path.as_posix()]
+    tester.execute(" ".join(options))
+
+    pyproject_file = path / "pyproject.toml"
+
+    expected = f"""\
+[tool.poetry.dependencies]
+python = "^{python}"
+"""
+
+    assert expected in pyproject_file.read_text()