Pyflakes fixes.

__init__.py

@@ -2,12 +2,12 @@
 # The COPYRIGHT file at the top level of this repository contains the full
 # copyright notices and license terms.
 from trytond.pool import Pool
-from .sale import *
-from .payment_type import *
+from . import sale
+from . import payment_type
 
 
 def register():
     Pool.register(
-        Sale,
-        PaymentType,
+        sale.Sale,
+        payment_type.PaymentType,
         module='sale_payment_type_cost', type_='model')

payment_type.py

@@ -4,8 +4,6 @@ from trytond.model import fields
 from trytond.pool import PoolMeta
 from trytond.pyson import Bool, Eval, Not, Or
 
-__all__ = ['PaymentType']
-
 
 class PaymentType(metaclass=PoolMeta):
     __name__ = 'account.payment.type'

sale.py

@@ -3,8 +3,6 @@
 # copyright notices and license terms.
 from trytond.pool import Pool, PoolMeta
 
-__all__ = ['Sale']
-
 
 class Sale(metaclass=PoolMeta):
     __name__ = 'sale.sale'