Migrate to py3

carrier.py

@@ -17,8 +17,7 @@ __all__ = ['Carrier', 'FormulaPriceList']
 DIGITS = config_.getint('product', 'price_decimal', default=4)
 
 
-class Carrier:
-    __metaclass__ = PoolMeta
+class Carrier(metaclass=PoolMeta):
     __name__ = 'carrier'
     formula_currency = fields.Many2One('currency.currency', 'Currency',
         states={

sale.py

@@ -6,8 +6,7 @@ from trytond.pool import PoolMeta
 __all__ = ['Sale']
 
 
-class Sale:
-    __metaclass__ = PoolMeta
+class Sale(metaclass=PoolMeta):
     __name__ = 'sale.sale'
 
     def _get_carrier_context(self):

setup.py

@@ -7,10 +7,7 @@ from setuptools import setup
 import re
 import os
 import io
-try:
-    from configparser import ConfigParser
-except ImportError:
-    from ConfigParser import ConfigParser
+from configparser import ConfigParser
 
 MODULE = 'carrier_formula'
 PREFIX = 'trytonzz'

stock.py

@@ -28,8 +28,7 @@ def _formula_amount(lines, company):
     return amount
 
 
-class ShipmentIn:
-    __metaclass__ = PoolMeta
+class ShipmentIn(metaclass=PoolMeta):
     __name__ = 'stock.shipment.in'
 
     def _get_carrier_context(self):
@@ -47,8 +46,7 @@ class ShipmentIn:
         return context
 
 
-class ShipmentOut:
-    __metaclass__ = PoolMeta
+class ShipmentOut(metaclass=PoolMeta):
     __name__ = 'stock.shipment.out'
 
     def _get_carrier_context(self):