add from __future__ import annotations to remove string literals around forward refs, remove some unused imports

Signed-off-by: varun-edachali-dbx <varun.edachali@databricks.com>

Author: varun-edachali-dbx

src/databricks/sql/backend/databricks_client.py

@@ -8,22 +8,17 @@
 - Fetching metadata about catalogs, schemas, tables, and columns
 """
 
+from __future__ import annotations
+
 from abc import ABC, abstractmethod
-from typing import Dict, Tuple, List, Optional, Any, Union, TYPE_CHECKING
+from typing import Dict, List, Optional, Any, Union, TYPE_CHECKING
 
 if TYPE_CHECKING:
     from databricks.sql.client import Cursor
+    from databricks.sql.result_set import ResultSet
 
 from databricks.sql.thrift_api.TCLIService import ttypes
 from databricks.sql.backend.types import SessionId, CommandId, CommandState
-from databricks.sql.utils import ExecuteResponse
-from databricks.sql.types import SSLOptions
-
-# Forward reference for type hints
-from typing import TYPE_CHECKING
-
-if TYPE_CHECKING:
-    from databricks.sql.result_set import ResultSet
 
 
 class DatabricksClient(ABC):
@@ -82,12 +77,12 @@ def execute_command(
         max_rows: int,
         max_bytes: int,
         lz4_compression: bool,
-        cursor: "Cursor",
+        cursor: Cursor,
         use_cloud_fetch: bool,
         parameters: List[ttypes.TSparkParameter],
         async_op: bool,
         enforce_embedded_schema_correctness: bool,
-    ) -> Union["ResultSet", None]:
+    ) -> Union[ResultSet, None]:
         """
         Executes a SQL command or query within the specified session.
 
@@ -177,8 +172,8 @@ def get_query_state(self, command_id: CommandId) -> CommandState:
     def get_execution_result(
         self,
         command_id: CommandId,
-        cursor: "Cursor",
-    ) -> "ResultSet":
+        cursor: Cursor,
+    ) -> ResultSet:
         """
         Retrieves the results of a previously executed command.
 
@@ -205,8 +200,8 @@ def get_catalogs(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
-    ) -> "ResultSet":
+        cursor: Cursor,
+    ) -> ResultSet:
         """
         Retrieves a list of available catalogs.
 
@@ -234,10 +229,10 @@ def get_schemas(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
+        cursor: Cursor,
         catalog_name: Optional[str] = None,
         schema_name: Optional[str] = None,
-    ) -> "ResultSet":
+    ) -> ResultSet:
         """
         Retrieves a list of schemas, optionally filtered by catalog and schema name patterns.
 
@@ -267,12 +262,12 @@ def get_tables(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
+        cursor: Cursor,
         catalog_name: Optional[str] = None,
         schema_name: Optional[str] = None,
         table_name: Optional[str] = None,
         table_types: Optional[List[str]] = None,
-    ) -> "ResultSet":
+    ) -> ResultSet:
         """
         Retrieves a list of tables, optionally filtered by catalog, schema, table name, and table types.
 
@@ -304,12 +299,12 @@ def get_columns(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
+        cursor: Cursor,
         catalog_name: Optional[str] = None,
         schema_name: Optional[str] = None,
         table_name: Optional[str] = None,
         column_name: Optional[str] = None,
-    ) -> "ResultSet":
+    ) -> ResultSet:
         """
         Retrieves a list of columns, optionally filtered by catalog, schema, table, and column name patterns.
 

src/databricks/sql/backend/thrift_backend.py

@@ -1,4 +1,3 @@
-from decimal import Decimal
 import errno
 import logging
 import math

src/databricks/sql/result_set.py

@@ -1,10 +1,12 @@
+from __future__ import annotations
+
 from abc import ABC, abstractmethod
-from typing import List, Optional, Any, Union, TYPE_CHECKING
+from typing import List, Optional, TYPE_CHECKING
 
 import logging
-import time
 import pandas
 
+from databricks.sql.backend.databricks_client import DatabricksClient
 from databricks.sql.backend.types import CommandId, CommandState
 
 try:
@@ -13,13 +15,11 @@
     pyarrow = None
 
 if TYPE_CHECKING:
-    from databricks.sql.backend.databricks_client import DatabricksClient
     from databricks.sql.backend.thrift_backend import ThriftDatabricksClient
     from databricks.sql.client import Connection
 
-from databricks.sql.thrift_api.TCLIService import ttypes
 from databricks.sql.types import Row
-from databricks.sql.exc import Error, RequestError, CursorAlreadyClosedError
+from databricks.sql.exc import RequestError, CursorAlreadyClosedError
 from databricks.sql.utils import ExecuteResponse, ColumnTable, ColumnQueue
 
 logger = logging.getLogger(__name__)
@@ -34,8 +34,8 @@ class ResultSet(ABC):
 
     def __init__(
         self,
-        connection: "Connection",
-        backend: "DatabricksClient",
+        connection: Connection,
+        backend: DatabricksClient,
         command_id: CommandId,
         op_state: Optional[CommandState],
         has_been_closed_server_side: bool,
@@ -139,9 +139,9 @@ class ThriftResultSet(ResultSet):
 
     def __init__(
         self,
-        connection: "Connection",
+        connection: Connection,
         execute_response: ExecuteResponse,
-        thrift_client: "ThriftDatabricksClient",
+        thrift_client: ThriftDatabricksClient,
         buffer_size_bytes: int = 104857600,
         arraysize: int = 10000,
         use_cloud_fetch: bool = True,

src/databricks/sql/session.py

@@ -9,7 +9,7 @@
 from databricks.sql import USER_AGENT_NAME
 from databricks.sql.backend.thrift_backend import ThriftDatabricksClient
 from databricks.sql.backend.databricks_client import DatabricksClient
-from databricks.sql.backend.types import SessionId, BackendType
+from databricks.sql.backend.types import SessionId
 
 logger = logging.getLogger(__name__)