style: fix lint issues in blocks.py and test_blocks_unpivot.py

Author: shuoweil

bigframes/core/blocks.py

@@ -160,7 +160,7 @@ def __init__(
         )
         self._expr = self._normalize_expression(expr, self._index_columns)
 
-        # FIX: Calculate value_columns after normalizing expression
+        # Calculate value_columns after normalizing expression
         actual_value_columns = [
             column
             for column in self._expr.column_ids
@@ -174,7 +174,7 @@ def __init__(
             else pd.Index(column_labels)
         )
 
-        # FIX: Adjust column_labels if needed to match actual_value_columns
+        # Adjust column_labels if needed to match actual_value_columns
         if len(actual_value_columns) != len(self._column_labels):
             # If we have more value columns than labels, extend with None
             if len(actual_value_columns) > len(self._column_labels):
@@ -191,7 +191,8 @@ def __init__(
         # Re-validate after adjustment
         if len(actual_value_columns) != len(self._column_labels):
             raise ValueError(
-                f"'value_columns' (size {len(actual_value_columns)}) and 'column_labels' (size {len(self._column_labels)}) must have equal length"
+                f"'value_columns' (size {len(actual_value_columns)}) and "
+                f"'column_labels' (size {len(self._column_labels)}) must have equal length"
             )
 
         # Update value_columns property to use actual_value_columns

tests/unit/core/test_blocks_unpivot.py

@@ -15,6 +15,7 @@
 from unittest import mock
 
 import pandas as pd
+import pyarrow as pa
 import pytest
 
 from bigframes.core import blocks
@@ -28,8 +29,7 @@ def mock_session():
 
 
 def test_pd_index_to_array_value_with_empty_index_creates_no_columns(mock_session):
-    """
-    Tests that `_pd_index_to_array_value` with an empty pandas Index creates
+    """Tests that `_pd_index_to_array_value` with an empty pandas Index creates
     an ArrayValue with the expected number of columns (index level + offset).
     """
     empty_index = pd.Index([], name="test")
@@ -41,8 +41,7 @@ def test_pd_index_to_array_value_with_empty_index_creates_no_columns(mock_sessio
 
 
 def test_pd_index_to_array_value_with_empty_multiindex_creates_no_columns(mock_session):
-    """
-    Tests that `_pd_index_to_array_value` with an empty pandas MultiIndex creates
+    """Tests that `_pd_index_to_array_value` with an empty pandas MultiIndex creates
     an ArrayValue with the expected number of columns (index levels + offset).
     """
     empty_index = pd.MultiIndex.from_arrays([[], []], names=["a", "b"])
@@ -54,11 +53,7 @@ def test_pd_index_to_array_value_with_empty_multiindex_creates_no_columns(mock_s
 
 
 def test_unpivot_with_empty_row_labels(mock_session):
-    """
-    Tests that `unpivot` handles an empty `row_labels` index correctly by producing 0 rows.
-    """
-    import pyarrow as pa
-
+    """Tests that `unpivot` handles an empty `row_labels` index correctly by producing 0 rows."""
     # Create a dummy ArrayValue
     df = pd.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
     pa_table = pa.Table.from_pandas(df)