ran linting + updated docstring in ddl function

Author: akkik04

clickhouse_connect/driver/ddl.py

@@ -29,7 +29,7 @@ def create_table(table_name: str, columns: Sequence[TableColumnDef], engine: str
     return stmt
 
 
-def _arrow_type_to_ch(arrow_type: "pa.DataType") -> str:
+def _arrow_type_to_ch(arrow_type: "pa.DataType") -> str: # pylint: disable=too-many-return-statements
     """
     Best-effort mapping from common PyArrow types to ClickHouse type names.
 
@@ -99,9 +99,10 @@ def arrow_schema_to_column_defs(schema: "pa.Schema") -> list[TableColumnDef]:
     non-nullable ClickHouse types, even though Arrow fields are nullable by
     default.
 
-    If the user later inserts an Arrow table that contains nulls, ClickHouse
-    will raise an error for that insert, and the user can adjust the DDL
-    (e.g. wrap specific types in Nullable(...)) to match their data.
+    Note that if the user inserts a table with nulls into a non-Nullable column,
+    ClickHouse will silently convert those nulls to default values due to the default
+    server setting input_format_null_as_default=1 and current lack of client-side
+    validation on arrow inserts.
     """
     pa = check_arrow()
 

tests/integration_tests/test_pyarrow_ddl_integration.py

@@ -1,17 +1,15 @@
 import pytest
-
-from clickhouse_connect.driver import Client
-
-pytest.importorskip("pyarrow")
-
 import pyarrow as pa
 
+from clickhouse_connect.driver import Client
 from clickhouse_connect.driver.ddl import (
     arrow_schema_to_column_defs,
     create_table,
     create_table_from_arrow_schema,
 )
 
+pytest.importorskip("pyarrow")
+
 
 def test_arrow_create_table_and_insert(test_client: Client):
     if not test_client.min_version("20"):
@@ -20,9 +18,9 @@ def test_arrow_create_table_and_insert(test_client: Client):
         )
 
     table_name = "test_arrow_basic_integration"
-    
+
     test_client.command(f"DROP TABLE IF EXISTS {table_name}")
-    
+
     schema = pa.schema(
         [
             ("id", pa.int64()),

tests/unit_tests/test_pyarrow_ddl.py

@@ -1,7 +1,4 @@
 import pytest
-
-pytest.importorskip("pyarrow")
-
 import pyarrow as pa
 
 from clickhouse_connect.driver.ddl import (
@@ -10,6 +7,8 @@
     create_table_from_arrow_schema,
 )
 
+pytest.importorskip("pyarrow")
+
 
 def test_arrow_schema_to_column_defs_basic_mappings():
     schema = pa.schema(