Synchronize with trytond pyson

proteus/pyson.py

@@ -24,7 +24,7 @@ class PYSON(object):
         raise NotImplementedError
 
     def __invert__(self):
-        if self.types() != set([bool]):
+        if self.types()!= set([bool]):
             return Not(Bool(self))
         else:
             return Not(self)
@@ -309,8 +309,7 @@ class If(PYSON):
     def __init__(self, condition, then_statement, else_statement=None):
         super(If, self).__init__()
         if isinstance(condition, PYSON):
-            assert condition.types() == set([bool]), \
-                'condition must be boolean'
+            assert condition.types() == set([bool]), 'condition must be boolean'
         else:
             assert isinstance(condition, bool), 'condition must be boolean'
         if isinstance(then_statement, PYSON):