def drop_unique_constraint(migrate_engine, table_name, uc_name, *columns, **col_name_col_instance):
 if (migrate_engine.name in ['mysql', 'postgresql']):
  meta = MetaData()
  meta.bind = migrate_engine
  t = Table(table_name, meta, autoload=True)
  uc = UniqueConstraint(table=t, name=uc_name, *columns)
  uc.drop()
 else:
  _drop_unique_constraint_in_sqlite(migrate_engine, table_name, uc_name, **col_name_col_instance)

def drop_unique_constraint ( migrate_engine , table_name , uc_name , * columns , ** col_name_col_instance ) : if ( migrate_engine . name in [ 'mysql' , 'postgresql' ] ) : meta = MetaData ( ) meta . bind = migrate_engine t = Table ( table_name , meta , autoload = True ) uc = UniqueConstraint ( table = t , name = uc_name , * columns ) uc . drop ( ) else : _drop_unique_constraint_in_sqlite ( migrate_engine , table_name , uc_name , ** col_name_col_instance )
this method drops uc from table and works for mysql .