fix flake8 errors from latest PRs

Author: tswast

pybigquery/sqlalchemy_bigquery.py

@@ -426,10 +426,20 @@ def _table_reference(self, provided_schema_name, provided_table_name,
                 raise ValueError("Did not understand schema: {}".format(provided_schema_name))
         if (dataset_id_from_schema and dataset_id_from_table and
            dataset_id_from_schema != dataset_id_from_table):
-            raise ValueError("dataset_id specified in schema and table_name disagree: got {} in schema, and {} in table_name".format(dataset_id_from_schema, dataset_id_from_table))
+            raise ValueError(
+                "dataset_id specified in schema and table_name disagree: "
+                "got {} in schema, and {} in table_name".format(
+                    dataset_id_from_schema, dataset_id_from_table
+                )
+            )
         if (project_id_from_schema and project_id_from_table and
            project_id_from_schema != project_id_from_table):
-            raise ValueError("project_id specified in schema and table_name disagree: got {} in schema, and {} in table_name".format(project_id_from_schema, project_id_from_table))
+            raise ValueError(
+                "project_id specified in schema and table_name disagree: "
+                "got {} in schema, and {} in table_name".format(
+                    project_id_from_schema, project_id_from_table
+                )
+            )
         project_id = project_id_from_schema or project_id_from_table or client_project
         dataset_id = dataset_id_from_schema or dataset_id_from_table or self.dataset_id
 

test/test_sqlalchemy_bigquery.py

@@ -314,8 +314,8 @@ def test_nested_labels(engine, table):
     col = table.c.integer
     exprs = [
         sqlalchemy.func.sum(
-            sqlalchemy.func.sum(col.label("inner")
-        ).label("outer")).over(),
+            sqlalchemy.func.sum(col.label("inner")).label("outer")
+        ).over(),
         sqlalchemy.func.sum(
             sqlalchemy.case([[
                 sqlalchemy.literal(True),
@@ -346,7 +346,10 @@ def test_session_query(session, table, session_using_test_dataset, table_using_t
                 table.c.string,
                 col_concat,
                 func.avg(table.c.integer),
-                func.sum(case([(table.c.boolean is True, 1)], else_=0))
+                func.sum(case(
+                    [(table.c.boolean == sqlalchemy.literal(True), 1)],
+                    else_=0
+                ))
             )
             .group_by(table.c.string, col_concat)
             .having(func.avg(table.c.integer) > 10)
@@ -557,6 +560,7 @@ def test_table_reference(dialect, provided_schema_name,
     assert ref.dataset_id == 'dataset'
     assert ref.project == 'project'
 
+
 @pytest.mark.parametrize('provided_schema_name,provided_table_name,client_project',
                          [
                              ('project.dataset', 'other_dataset.table', 'project'),