lib.init.detect_modules(): Add function

Not all __init__.py modules are generated by python-tools.sh, some are needed early to make jw-pkg useful without generation, notably in jw.pkg.cmds.
Add detect_modules() to unify that detection, and place it into a minimal module lib.init to not increase startup time cost.
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/cmds/__init__.py

@@ -1,13 +1,9 @@
-import importlib, pkgutil
+from ..lib.init import detect_modules
 
-__all__ = []
-
-for finder, module_name, ispkg in pkgutil.iter_modules(__path__):
-    if not module_name.startswith("Cmd"):
-        continue
-    if  module_name == "Cmd":
-        continue
-    module = importlib.import_module(f".{module_name}", __name__)
-    cls = getattr(module, module_name)
-    globals()[module_name] = cls
-    __all__.append(module_name)
+__all__ = detect_modules(
+    package_name = __name__,
+    package_path = __path__,
+    namespace = globals(),
+    prefix = "Cmd",
+    skip = {"Cmd"},
+) # pyright: ignore[reportUnsupportedDunderAll]

src/python/jw/pkg/cmds/pkg/__init__.py

@@ -1,11 +1,9 @@
-import importlib, pkgutil
+from ...lib.init import detect_modules
 
-__all__ = []
-
-for finder, module_name, ispkg in pkgutil.iter_modules(__path__):
-    if not module_name.startswith("Cmd"):
-        continue
-    module = importlib.import_module(f".{module_name}", __name__)
-    cls = getattr(module, module_name)
-    globals()[module_name] = cls
-    __all__.append(module_name)
+__all__ = detect_modules(
+    package_name = __name__,
+    package_path = __path__,
+    namespace = globals(),
+    prefix = "Cmd",
+    skip = {"Cmd"},
+) # pyright: ignore[reportUnsupportedDunderAll]

src/python/jw/pkg/cmds/platform/__init__.py

@@ -1,11 +1,9 @@
-import importlib, pkgutil
+from ...lib.init import detect_modules
 
-__all__ = []
-
-for finder, module_name, ispkg in pkgutil.iter_modules(__path__):
-    if not module_name.startswith("Cmd"):
-        continue
-    module = importlib.import_module(f".{module_name}", __name__)
-    cls = getattr(module, module_name)
-    globals()[module_name] = cls
-    __all__.append(module_name)
+__all__ = detect_modules(
+    package_name = __name__,
+    package_path = __path__,
+    namespace = globals(),
+    prefix = "Cmd",
+    skip = {"Cmd"},
+) # pyright: ignore[reportUnsupportedDunderAll]

src/python/jw/pkg/cmds/projects/__init__.py

@@ -1,11 +1,9 @@
-import importlib, pkgutil
+from ...lib.init import detect_modules
 
-__all__ = []
-
-for finder, module_name, ispkg in pkgutil.iter_modules(__path__):
-    if not module_name.startswith("Cmd"):
-        continue
-    module = importlib.import_module(f".{module_name}", __name__)
-    cls = getattr(module, module_name)
-    globals()[module_name] = cls
-    __all__.append(module_name)
+__all__ = detect_modules(
+    package_name = __name__,
+    package_path = __path__,
+    namespace = globals(),
+    prefix = "Cmd",
+    skip = {"Cmd"},
+) # pyright: ignore[reportUnsupportedDunderAll]

src/python/jw/pkg/lib/init.py

@@ -0,0 +1,36 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import MutableMapping
+    from typing import Any, Iterable
+
+def detect_modules(
+    package_name: str,
+    package_path: Iterable[str],
+    namespace: MutableMapping[str, Any],
+    prefix: str,
+    skip: set[str] | None = None,
+) -> list[str]:
+
+    import importlib
+    import pkgutil
+
+    ret: list[str] = []
+    skip = skip or set()
+
+    for _finder, module_name, _ispkg in pkgutil.iter_modules(package_path):
+        if not module_name.startswith(prefix):
+            continue
+
+        if module_name in skip:
+            continue
+
+        module = importlib.import_module(f'.{module_name}', package_name)
+        cls = getattr(module, module_name)
+
+        namespace[module_name] = cls
+        ret.append(module_name)
+
+    return ret