[hotfix] resolve utf-8 encoding issue in db migration (#4461)

* [hotfix] resolve utf-8 encoding issue in db migration

* make python string unicode

* Update e866bd2d4976_smaller_grid.py

* Update e866bd2d4976_smaller_grid.py

* rearrange the debug message

* Update e866bd2d4976_smaller_grid.py

superset/migrations/versions/e866bd2d4976_smaller_grid.py

@@ -32,6 +32,8 @@ def upgrade():
 
     dashboards = session.query(Dashboard).all()
     for i, dashboard in enumerate(dashboards):
+        print('Upgrading ({}/{}): {}'.format(
+            i, len(dashboards), dashboard.id))
         positions = json.loads(dashboard.position_json or '{}')
         for pos in positions:
             if pos.get('v', 0) == 0:
@@ -44,8 +46,6 @@ def upgrade():
         dashboard.position_json = json.dumps(positions, indent=2)
         session.merge(dashboard)
         session.commit()
-        print('Upgraded ({}/{}): {}'.format(
-            i, len(dashboards), dashboard.dashboard_title))
 
     session.close()
 
@@ -56,6 +56,8 @@ def downgrade():
 
     dashboards = session.query(Dashboard).all()
     for i, dashboard in enumerate(dashboards):
+        print('Downgrading ({}/{}): {}'.format(
+            i, len(dashboards), dashboard.id))
         positions = json.loads(dashboard.position_json or '{}')
         for pos in positions:
             if pos.get('v', 0) == 1:
@@ -68,6 +70,4 @@ def downgrade():
         dashboard.position_json = json.dumps(positions, indent=2)
         session.merge(dashboard)
         session.commit()
-        print('Downgraded ({}/{}): {}'.format(
-            i, len(dashboards), dashboard.dashboard_title))
     pass