works

migrations/script.py.mako

@@ -5,24 +5,20 @@ Revises: ${down_revision | comma,n}
 Create Date: ${create_date}
 
 """
-from typing import Sequence, Union
-
 from alembic import op
 import sqlalchemy as sa
 ${imports if imports else ""}
 
 # revision identifiers, used by Alembic.
-revision: str = ${repr(up_revision)}
-down_revision: Union[str, Sequence[str], None] = ${repr(down_revision)}
-branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
-depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
 
 
-def upgrade() -> None:
-    """Upgrade schema."""
+def upgrade():
     ${upgrades if upgrades else "pass"}
 
 
-def downgrade() -> None:
-    """Downgrade schema."""
+def downgrade():
     ${downgrades if downgrades else "pass"}