Pyflakes fixes

production.py

@@ -4,16 +4,8 @@ from trytond.pool import Pool, PoolMeta
 from trytond.model import (Workflow, ModelView, fields, MultiValueMixin,
     ValueMixin, ModelSQL, dualmethod)
 from trytond.pyson import Eval, Bool
-from trytond import backend
-from trytond.transaction import Transaction
 from trytond.i18n import gettext
 from trytond.exceptions import UserError
-from trytond.modules.product import round_price
-from decimal import Decimal
-
-
-__all__ = ['Party', 'PurchaseRequest', 'BOM', 'Production', 'Purchase',
-    'PartyProductionWarehouse']
 
 
 class Party(MultiValueMixin, metaclass=PoolMeta):