diff --git a/__init__.py b/__init__.py
index d08bd5618a..89802f84de 100644
--- a/__init__.py
+++ b/__init__.py
@@ -1,5 +1,5 @@
-#This file is part of Tryton.  The COPYRIGHT file at the top level of
-#this repository contains the full copyright notices and license terms.
+# This file is part of Tryton.  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 *
diff --git a/sale.py b/sale.py
index 8bde6c4c6f..44cf9be686 100644
--- a/sale.py
+++ b/sale.py
@@ -1,8 +1,7 @@
-#This file is part of Tryton.  The COPYRIGHT file at the top level of
-#this repository contains the full copyright notices and license terms.
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
 from trytond.model import fields
 from trytond.pyson import Eval
-from trytond.transaction import Transaction
 from trytond.pool import Pool, PoolMeta
 
 __all__ = ['SaleLine', 'Account']
diff --git a/setup.py b/setup.py
index b45d82a951..7671beb570 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
-#This file is part of Tryton.  The COPYRIGHT file at the top level of
-#this repository contains the full copyright notices and license terms.
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
 
 from setuptools import setup
 import re
diff --git a/tests/__init__.py b/tests/__init__.py
index ce62a2aa1c..7e53c85fa2 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -1,5 +1,5 @@
-#This file is part of Tryton.  The COPYRIGHT file at the top level of
-#this repository contains the full copyright notices and license terms.
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
 
 from .test_analytic_sale import suite
 
diff --git a/tests/test_analytic_sale.py b/tests/test_analytic_sale.py
index 252a90681a..1230e5d23a 100644
--- a/tests/test_analytic_sale.py
+++ b/tests/test_analytic_sale.py
@@ -1,5 +1,5 @@
-#This file is part of Tryton.  The COPYRIGHT file at the top level of
-#this repository contains the full copyright notices and license terms.
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
 import unittest
 import trytond.tests.test_tryton
 from trytond.tests.test_tryton import test_view, test_depends