TOW-1131 - add py.typed to python sdk (#127)

* chore: add py.typed to SDK

* feat: add type checking for optional imports

Author: socksy

.github/workflows/test-python.yml

@@ -38,5 +38,8 @@ jobs:
       - name: Check Python formatting with Black
         run: uv run --group dev black --check --diff .
 
+      - name: Check types with mypy
+        run: uv run --group dev mypy src/tower/__init__.py --no-error-summary
+
       - name: Run tests
         run: uv run pytest tests

pyproject.toml

@@ -105,6 +105,7 @@ test = [
 dev = [
   { include-group = "test" },
   "black==24.10.0",
+  "mypy==1.13.0",
   "openapi-python-client==0.24.3",
   "pre-commit==4.0.1",
   "pyiceberg[sql-sqlite]==0.9.1",

src/tower/__init__.py

@@ -11,6 +11,8 @@
 - All features: Install with `pip install "tower[all]"`
 """
 
+from typing import TYPE_CHECKING
+
 from ._client import (
     run_app,
     wait_for_run,
@@ -19,8 +21,13 @@
 
 from ._features import override_get_attr, get_available_features, is_feature_enabled
 
+if TYPE_CHECKING:
+    from ._tables import tables as tables
+    from ._llms import llms as llms
+    from ._dbt import dbt as dbt
+
 
-def __getattr__(name: str) -> any:
+def __getattr__(name: str):
     """
     Dynamic attribute lookup for optional features.