Add reversed operators to PYSON expressions

review15551002
issue4856

CHANGELOG

@@ -1,3 +1,5 @@
+* Add reversed operators to PYSON expressions
+
 Version 3.6.0 - 2015-04-20
 * Bug fixes (see mercurial logs for details)
 * Hide columns containing always the same value

tryton/pyson.py

@@ -56,6 +56,8 @@ class PYSON(object):
         else:
             return And(self, other)
 
+    __rand__ = __and__
+
     def __or__(self, other):
         if (isinstance(other, PYSON)
                 and other.types() != set([bool])):
@@ -68,6 +70,8 @@ class PYSON(object):
         else:
             return Or(self, other)
 
+    __ror__ = __or__
+
     def __eq__(self, other):
         return Equal(self, other)