fix: Create __init__ files for the proto-generated python dirs

Signed-off-by: Achal Shah <achals@gmail.com>

Makefile

@@ -46,7 +46,7 @@ package-protos:
 	cp -r ${ROOT_DIR}/protos ${ROOT_DIR}/sdk/python/feast/protos
 
 compile-protos-python:
-	python setup.py build_python_protos
+	python sdk/python/setup.py build_python_protos
 
 install-python:
 	cd sdk/python && python -m piptools sync requirements/py$(PYTHON)-requirements.txt

sdk/python/setup.py

@@ -210,13 +210,21 @@ def _generate_python_protos(self, path: str):
                 self.python_folder,
             ]
             + proto_files,
-        )
+            )
 
     def run(self):
+        from pathlib import Path
+
         for sub_folder in self.sub_folders:
             self._generate_python_protos(f"feast/{sub_folder}/*.proto")
-
-        from pathlib import Path
+            # We need the __init__ files for each of the generated subdirs
+            # so that they are regular packages, and don't need the `--namespace-packages` flags
+            # when being typechecked using mypy. BUT, we need to exclude `types` because that clashes
+            # with an existing module in the python standard library.
+            if sub_folder == "types":
+                continue
+            with open(f"{self.python_folder}/feast/{sub_folder}/__init__.py", 'w'):
+                pass
 
         for path in Path("feast/protos").rglob("*.py"):
             for folder in self.sub_folders: