--- a/cubicweb/server/sources/native.py	Wed Apr 12 16:12:51 2017 +0200
+++ b/cubicweb/server/sources/native.py	Wed Apr 12 16:14:10 2017 +0200
@@ -229,7 +229,7 @@
                 return self._create_eid(count)
             else:
                 raise
-        except Exception: # WTF?
+        except Exception:  # WTF?
             cnx.rollback()
             self.cnx = None
             source.exception('create eid failed in an unforeseen way on SQL statement %s', sql)
@@ -704,7 +704,7 @@
                         raise UniqueTogetherError(cnx, cstrname=mo.group(0))
                     # old sqlite
                     mo = re.search('columns? (.*) (?:is|are) not unique', arg)
-                    if mo is not None: # sqlite in use
+                    if mo is not None:  # sqlite in use
                         # we left chop the 'cw_' prefix of attribute names
                         rtypes = [c.strip()[3:]
                                   for c in mo.group(1).split(',')]
@@ -1649,12 +1649,12 @@
             self.logger.critical('Restore warning: versions do not match')
             new_cubes = db_versions - archive_versions
             if new_cubes:
-                self.logger.critical('In the db:\n%s', '\n'.join('%s: %s' % (cube, ver)
-                                                            for cube, ver in sorted(new_cubes)))
+                self.logger.critical('In the db:\n%s', '\n'.join(
+                    '%s: %s' % (cube, ver) for cube, ver in sorted(new_cubes)))
             old_cubes = archive_versions - db_versions
             if old_cubes:
-                self.logger.critical('In the archive:\n%s', '\n'.join('%s: %s' % (cube, ver)
-                                                            for cube, ver in sorted(old_cubes)))
+                self.logger.critical('In the archive:\n%s', '\n'.join(
+                    '%s: %s' % (cube, ver) for cube, ver in sorted(old_cubes)))
             if not ASK.confirm('Versions mismatch: continue anyway ?', False):
                 raise ValueError('Unable to restore: versions do not match')
         table_chunks = {}