fix(py-sdk): fix type annotations

examples/text_embedding/main.py

@@ -25,7 +25,7 @@ def text_to_embedding(
 @cocoindex.flow_def(name="TextEmbedding")
 def text_embedding_flow(
     flow_builder: cocoindex.FlowBuilder, data_scope: cocoindex.DataScope
-):
+) -> None:
     """
     Define an example flow that embeds text into a vector database.
     """
@@ -65,7 +65,7 @@ def text_embedding_flow(
     )
 
 
-def search(pool: ConnectionPool, query: str, top_k: int = 5):
+def search(pool: ConnectionPool, query: str, top_k: int = 5) -> list[dict[str, Any]]:
     # Get the table name, for the export target in the text_embedding_flow above.
     table_name = cocoindex.utils.get_target_default_name(
         text_embedding_flow, "doc_embeddings"
@@ -89,7 +89,7 @@ def search(pool: ConnectionPool, query: str, top_k: int = 5):
             ]
 
 
-def _main():
+def _main() -> None:
     # Initialize the database connection pool.
     pool = ConnectionPool(os.getenv("COCOINDEX_DATABASE_URL"))
     # Run queries in a loop to demonstrate the query capabilities.

python/cocoindex/flow.py

@@ -185,7 +185,7 @@ def for_each(self, f: Callable[[DataScope], None]) -> None:
 
     def transform(
         self, fn_spec: op.FunctionSpec, *args: Any, **kwargs: Any
-    ) -> DataSlice[T]:
+    ) -> DataSlice[Any]:
         """
         Apply a function to the data slice.
         """