diff --git a/aerich/__init__.py b/aerich/__init__.py
index 2eec79c..7e256ed 100644
--- a/aerich/__init__.py
+++ b/aerich/__init__.py
@@ -102,11 +102,8 @@ class Command:
         return ret
 
     async def history(self):
-        ret = []
         versions = Migrate.get_all_version_files()
-        for version in versions:
-            ret.append(version)
-        return ret
+        return [version for version in versions]
 
     async def inspectdb(self, tables: List[str] = None) -> str:
         connection = get_app_connection(self.tortoise_config, self.app)
diff --git a/aerich/ddl/__init__.py b/aerich/ddl/__init__.py
index 892d9e9..422287e 100644
--- a/aerich/ddl/__init__.py
+++ b/aerich/ddl/__init__.py
@@ -180,7 +180,7 @@ class BaseDDL:
                 "idx" if not unique else "uid", model, field_names
             ),
             table_name=model._meta.db_table,
-            column_names=", ".join([self.schema_generator.quote(f) for f in field_names]),
+            column_names=", ".join(self.schema_generator.quote(f) for f in field_names),
         )
 
     def drop_index(self, model: "Type[Model]", field_names: List[str], unique=False):
diff --git a/tests/test_ddl.py b/tests/test_ddl.py
index 9227161..c710b33 100644
--- a/tests/test_ddl.py
+++ b/tests/test_ddl.py
@@ -72,18 +72,16 @@ def test_modify_column():
     ret1 = Migrate.ddl.modify_column(User, User._meta.fields_map.get("is_active").describe(False))
     if isinstance(Migrate.ddl, MysqlDDL):
         assert ret0 == "ALTER TABLE `category` MODIFY COLUMN `name` VARCHAR(200)"
+        assert (
+            ret1
+            == "ALTER TABLE `user` MODIFY COLUMN `is_active` BOOL NOT NULL  COMMENT 'Is Active' DEFAULT 1"
+        )
     elif isinstance(Migrate.ddl, PostgresDDL):
         assert (
             ret0
             == 'ALTER TABLE "category" ALTER COLUMN "name" TYPE VARCHAR(200) USING "name"::VARCHAR(200)'
         )
 
-    if isinstance(Migrate.ddl, MysqlDDL):
-        assert (
-            ret1
-            == "ALTER TABLE `user` MODIFY COLUMN `is_active` BOOL NOT NULL  COMMENT 'Is Active' DEFAULT 1"
-        )
-    elif isinstance(Migrate.ddl, PostgresDDL):
         assert (
             ret1 == 'ALTER TABLE "user" ALTER COLUMN "is_active" TYPE BOOL USING "is_active"::BOOL'
         )