Added virtualenvs.prompt option to config

docs/configuration.md

@@ -51,6 +51,7 @@ virtualenvs.options.no-setuptools = false
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = "{cache-dir}/virtualenvs"  # /path/to/cache/directory/virtualenvs
 virtualenvs.prefer-active-python = false
+virtualenvs.prompt = "{project_name}-py{python_version}"
 ```
 
 ## Displaying a single configuration setting
@@ -219,6 +220,14 @@ existing `.venv` directory.
 Directory where virtual environments will be created.
 Defaults to `{cache-dir}/virtualenvs` (`{cache-dir}\virtualenvs` on Windows).
 
+### `virtualenvs.prompt`
+
+**Type**: string
+
+Format string defining the prompt to be displayed when the virtual environment is activated.
+The variables `project_name` and `python_version` are available for formatting.
+Defaults to `"{project_name}-py{python_version}"`.
+
 ### `virtualenvs.options.always-copy`
 
 **Type**: boolean

src/poetry/config/config.py

@@ -123,6 +123,7 @@ class Config:
                 "no-setuptools": False,
             },
             "prefer-active-python": False,
+            "prompt": "{project_name}-py{python_version}",
         },
         "experimental": {"new-installer": True, "system-git-client": False},
         "installer": {"parallel": True, "max-workers": None, "no-binary": None},
@@ -234,11 +235,17 @@ def process(self, value: Any) -> Any:
         if not isinstance(value, str):
             return value
 
-        return re.sub(
-            r"{(.+?)}",
-            lambda m: self.get(m.group(1)),  # type: ignore[no-any-return]
-            value,
-        )
+        def resolve_from_config(match: re.Match[str]) -> Any:
+            key = match.group(1)
+            config_value = self.get(key)
+            if config_value:
+                return config_value
+
+            # The key doesn't exist in the config but might be resolved later,
+            # so we keep it as a format variable.
+            return f"{{{key}}}"
+
+        return re.sub(r"{(.+?)}", resolve_from_config, value)
 
     @staticmethod
     def _get_normalizer(name: str) -> Callable[[str], Any]:

src/poetry/console/commands/config.py

@@ -108,6 +108,11 @@ def unique_config_values(self) -> dict[str, tuple[Any, Any, Any]]:
                 int_normalizer,
                 None,
             ),
+            "virtualenvs.prompt": (
+                str,
+                lambda val: str(val),
+                "{project_name}-py{python_version}",
+            ),
             "installer.no-binary": (
                 PackageFilterPolicy.validator,
                 PackageFilterPolicy.normalize,

src/poetry/utils/env.py

@@ -862,6 +862,7 @@ def create_venv(
         prefer_active_python = self._poetry.config.get(
             "virtualenvs.prefer-active-python"
         )
+        venv_prompt = self._poetry.config.get("virtualenvs.prompt")
 
         if not executable and prefer_active_python:
             executable = self._detect_active_python(io)
@@ -962,6 +963,11 @@ def create_venv(
             name = f"{name}-py{python_minor.strip()}"
             venv = venv_path / name
 
+        if venv_prompt is not None:
+            venv_prompt = venv_prompt.format(
+                project_name=self._poetry.package.name, python_version=python_minor
+            )
+
         if not venv.exists():
             if create_venv is False:
                 io.write_line(
@@ -993,6 +999,7 @@ def create_venv(
                 venv,
                 executable=executable,
                 flags=self._poetry.config.get("virtualenvs.options"),
+                prompt=venv_prompt,
             )
 
         # venv detection:
@@ -1022,6 +1029,7 @@ def build_venv(
         with_pip: bool | None = None,
         with_wheel: bool | None = None,
         with_setuptools: bool | None = None,
+        prompt: str | None = None,
     ) -> virtualenv.run.session.Session:
         flags = flags or {}
 
@@ -1053,6 +1061,9 @@ def build_venv(
             executable or sys.executable,
         ]
 
+        if prompt is not None:
+            args.extend(["--prompt", prompt])
+
         for flag, value in flags.items():
             if value is True:
                 args.append(f"--{flag}")

tests/console/commands/env/test_use.py

@@ -77,6 +77,7 @@ def test_activate_activates_non_existing_virtualenv_no_envs_file(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.7",
     )
 
     envs_file = TOMLFile(venv_cache / "envs.toml")

tests/console/commands/test_config.py

@@ -64,6 +64,7 @@ def test_list_displays_default_value_if_not_set(
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = {venv_path}  # {config_cache_dir / 'virtualenvs'}
 virtualenvs.prefer-active-python = false
+virtualenvs.prompt = "{{project_name}}-py{{python_version}}"
 """
 
     assert tester.io.fetch_output() == expected
@@ -92,6 +93,7 @@ def test_list_displays_set_get_setting(
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = {venv_path}  # {config_cache_dir / 'virtualenvs'}
 virtualenvs.prefer-active-python = false
+virtualenvs.prompt = "{{project_name}}-py{{python_version}}"
 """
 
     assert config.set_config_source.call_count == 0
@@ -144,6 +146,7 @@ def test_list_displays_set_get_local_setting(
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = {venv_path}  # {config_cache_dir / 'virtualenvs'}
 virtualenvs.prefer-active-python = false
+virtualenvs.prompt = "{{project_name}}-py{{python_version}}"
 """
 
     assert config.set_config_source.call_count == 1

tests/utils/test_env.py

@@ -218,6 +218,7 @@ def test_activate_activates_non_existing_virtualenv_no_envs_file(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.7",
     )
 
     envs_file = TOMLFile(Path(tmp_dir) / "envs.toml")
@@ -355,6 +356,7 @@ def test_activate_activates_different_virtualenv_with_envs_file(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.6",
     )
 
     assert envs_file.exists()
@@ -418,6 +420,7 @@ def test_activate_activates_recreates_for_different_patch(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.7",
     )
     remove_venv_m.assert_called_with(Path(tmp_dir) / f"{venv_name}-py3.7")
 
@@ -855,6 +858,7 @@ def test_create_venv_tries_to_find_a_compatible_python_executable_using_generic_
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.7",
     )
 
 
@@ -888,6 +892,7 @@ def test_create_venv_tries_to_find_a_compatible_python_executable_using_specific
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.9",
     )
 
 
@@ -980,6 +985,7 @@ def test_create_venv_uses_patch_version_to_detect_compatibility(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt=f"simple-project-py{version.major}.{version.minor}",
     )
 
 
@@ -1021,6 +1027,7 @@ def test_create_venv_uses_patch_version_to_detect_compatibility_with_executable(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt=f"simple-project-py{version.major}.{version.minor - 1}",
     )
 
 
@@ -1091,6 +1098,7 @@ def test_activate_with_in_project_setting_does_not_fail_if_no_venvs_dir(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.7",
     )
 
     envs_file = TOMLFile(Path(tmp_dir) / "virtualenvs" / "envs.toml")
@@ -1324,6 +1332,7 @@ def test_create_venv_accepts_fallback_version_w_nonzero_patchlevel(
             "no-pip": False,
             "no-setuptools": False,
         },
+        prompt="simple-project-py3.5",
     )