Clear updates/requirements after commit

Resolves apache#1946

Author: Fokko

pyiceberg/table/__init__.py

@@ -773,13 +773,15 @@ def commit_transaction(self) -> Table:
                 updates=self._updates,
                 requirements=self._requirements,
             )
+            self._updates = ()
+            self._requirements = ()
             return self._table
         else:
             return self._table
 
 
 class CreateTableTransaction(Transaction):
-    """A transaction that involves the creation of a a new table."""
+    """A transaction that involves the creation of a new table."""
 
     def _initial_changes(self, table_metadata: TableMetadata) -> None:
         """Set the initial changes that can reconstruct the initial table metadata when creating the CreateTableTransaction."""

tests/integration/test_writes/test_writes.py

@@ -1684,3 +1684,13 @@ def test_write_optional_list(session_catalog: Catalog) -> None:
     session_catalog.load_table(identifier).append(df_2)
 
     assert len(session_catalog.load_table(identifier).scan().to_arrow()) == 4
+
+
+@pytest.mark.integration
+def test_double_commit_transaction(spark: SparkSession, session_catalog: Catalog, arrow_table_with_null: pa.Table) -> None:
+    identifier = "default.arrow_data_files"
+    tbl = _create_table(session_catalog, identifier, {"format-version": "1"}, [])
+
+    with tbl.transaction() as tx:
+        tx.append(arrow_table_with_null)
+        tx.commit_transaction()