move py.typed to correct places

.github/workflows/code-quality-checks.yml

@@ -160,4 +160,7 @@ jobs:
       #              mypy the code
       #----------------------------------------------
       - name: Mypy
-        run: poetry run mypy --install-types --non-interactive src
+        run: |
+          cd src # Need to be in the actual databricks/ folder or mypy does the wrong thing.
+          mkdir .mypy_cache # Workaround for bad error message "error: --install-types failed (no mypy cache directory)"; see https://github.com/python/mypy/issues/10768#issuecomment-2178450153
+          poetry run mypy --config-file ../pyproject.toml --install-types --non-interactive --namespace-packages databricks

src/databricks/sql/utils.py

@@ -7,7 +7,7 @@
 from collections.abc import Iterable
 from decimal import Decimal
 from enum import Enum
-from typing import Any, Dict, List, Union
+from typing import Any, Dict, List, Optional, Union
 import re
 
 import lz4.frame
@@ -134,7 +134,7 @@ def __init__(
         schema_bytes,
         max_download_threads: int,
         start_row_offset: int = 0,
-        result_links: List[TSparkArrowResultLink] = None,
+        result_links: Optional[List[TSparkArrowResultLink]] = None,
         lz4_compressed: bool = True,
         description: List[List[Any]] = None,
     ):
@@ -168,11 +168,10 @@ def __init__(
                         result_link.startRowOffset, result_link.rowCount
                     )
                 )
-
-        self.download_manager = ResultFileDownloadManager(
-            self.max_download_threads, self.lz4_compressed
-        )
-        self.download_manager.add_file_links(result_links)
+            self.download_manager = ResultFileDownloadManager(
+                self.max_download_threads, self.lz4_compressed
+            )
+            self.download_manager.add_file_links(result_links)
 
         self.table = self._create_next_table()
         self.table_row_index = 0