Eliminate local imports where feasible

In the case of appose.__version__, this necessitated moving the version
string into a separate _version.py, to eliminate a circular dependency:

  appose.util (lowest - utilities)
    ↓
  appose.tool (uses utilities)
    ↓
  appose.builder (uses tools)
    ↓
  appose/__init__.py (highest - imports everything)

  The problem was util/download.py importing __version__ from the
  top-level package, violating this hierarchy.

  Solution: Moved __version__ to a foundational module like
  appose/_version.py or appose/version.py. Now:
  - appose/__init__.py imports and re-exports it
  - util/download.py imports it from the foundational module
  - No circular dependency

Author: ctrueden

src/appose/__init__.py

@@ -231,8 +231,7 @@ def task_listener(event):
 from .environment import Environment
 from .service import TaskException  # noqa: F401
 from .shm import NDArray, SharedMemory  # noqa: F401
-
-__version__ = "0.7.3.dev0"
+from ._version import __version__  # noqa: F401
 
 
 def pixi(source: str | Path | None = None) -> PixiBuilder:

src/appose/_version.py

@@ -0,0 +1,31 @@
+###
+# #%L
+# Appose: multi-language interprocess cooperation with shared memory.
+# %%
+# Copyright (C) 2023 - 2025 Appose developers.
+# %%
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+# #L%
+###
+
+"""Version information for Appose."""
+
+__version__ = "0.7.3.dev0"

src/appose/builder/__init__.py

@@ -45,9 +45,10 @@
 from typing import Callable
 from urllib.request import urlopen
 
+from .. import scheme
 from ..environment import Environment
 from ..scheme import Scheme
-from .. import scheme
+from ..util.filepath import appose_envs_dir
 
 
 # Type alias for progress callback
@@ -554,8 +555,6 @@ def _env_dir(self) -> Path:
         if self.env_dir:
             return self.env_dir
         # Fall back to Appose-managed environments directory
-        from ..util.filepath import appose_envs_dir
-
         return Path(appose_envs_dir()) / self._env_name()
 
     def _scheme(self) -> Scheme:

src/appose/builder/mamba.py

@@ -37,6 +37,7 @@
 
 from . import BaseBuilder, BuildException, Builder, BuilderFactory
 from ..environment import Environment
+from ..tool.mamba import Mamba
 
 
 class MambaBuilder(BaseBuilder):
@@ -78,8 +79,6 @@ def build(self) -> Environment:
         Raises:
             BuildException: If the build fails
         """
-        from ..tool.mamba import Mamba
-
         env_dir = self._env_dir()
 
         # Check for incompatible existing environments
@@ -192,7 +191,7 @@ def wrap(self, env_dir: str | Path) -> Environment:
         self.base(env_path)
         return self.build()
 
-    def _create_environment(self, env_dir: Path, mamba) -> Environment:
+    def _create_environment(self, env_dir: Path, mamba: Mamba) -> Environment:
         """
         Creates an Environment for the given Mamba/conda directory.
 

src/appose/builder/pixi.py

@@ -36,6 +36,7 @@
 
 from . import BaseBuilder, BuildException, Builder, BuilderFactory
 from ..environment import Environment
+from ..tool.pixi import Pixi
 
 
 class PixiBuilder(BaseBuilder):
@@ -105,8 +106,6 @@ def build(self) -> Environment:
         Raises:
             BuildException: If the build fails
         """
-        from ..tool.pixi import Pixi
-
         env_dir = self._env_dir()
 
         # Check for incompatible existing environments
@@ -285,7 +284,7 @@ def wrap(self, env_dir: str | Path) -> Environment:
         self.base(env_path)
         return self.build()
 
-    def _create_environment(self, env_dir: Path, pixi) -> Environment:
+    def _create_environment(self, env_dir: Path, pixi: Pixi) -> Environment:
         """
         Creates an Environment for the given Pixi directory.
 

src/appose/builder/uv.py

@@ -37,6 +37,8 @@
 
 from . import BaseBuilder, BuildException, Builder, BuilderFactory
 from ..environment import Environment
+from ..tool.uv import Uv
+from ..util.platform import is_windows
 
 
 class UvBuilder(BaseBuilder):
@@ -108,8 +110,6 @@ def build(self) -> Environment:
         Raises:
             BuildException: If the build fails
         """
-        from ..tool.uv import Uv
-
         env_dir = self._env_dir()
 
         # Check for incompatible existing environments
@@ -262,8 +262,6 @@ def _create_environment(self, env_dir: Path) -> Environment:
         Returns:
             Environment configured for this uv/venv installation
         """
-        from ..util.platform import is_windows
-
         # Convert to absolute path for consistency
         env_dir_abs = env_dir.absolute()
         base = str(env_dir_abs)

src/appose/tool/mamba.py

@@ -106,9 +106,7 @@ class Mamba(Tool):
 
     # URL from where Micromamba is downloaded to be installed
     DOWNLOAD_URL: str | None = (
-        f"https://micro.mamba.pm/api/micromamba/{PLATFORM}/latest"
-        if PLATFORM
-        else None
+        f"https://micro.mamba.pm/api/micromamba/{PLATFORM}/latest" if PLATFORM else None
     )
 
     def __init__(self, rootdir: str | None = None):

src/appose/util/download.py

@@ -19,7 +19,8 @@
 from typing import Callable
 from urllib.error import HTTPError
 
-from .. import __version__
+from .._version import __version__
+from .filepath import file_type
 
 
 def download(
@@ -41,7 +42,6 @@ def download(
     Raises:
         IOError: If download fails.
     """
-    from .filepath import file_type
 
     # Resolve redirects and get final URL
     final_url = redirected_url(url_path)

src/appose/util/proxy.py

@@ -57,6 +57,8 @@
 
 from typing import TYPE_CHECKING, Any
 
+from .. import syntax
+
 if TYPE_CHECKING:
     from ..service import Service
 
@@ -99,7 +101,6 @@ def create(service: Service, var: str, queue: str | None = None) -> Any:
     Raises:
         RuntimeError: If a proxied method call fails in the worker process.
     """
-    from .. import syntax
 
     class ProxyHandler:
         def __init__(self, service: Service, var: str, queue: str | None):