def opIsCommutative(self):
    'Return True if the operation is commutative'
    op = self.get_op()
    return ((op == 144) or (op == 146) or (op == 149) or (op == 150) or (op == 151) or (op == 155) or (op == 157) or (op == 160) or (op == 161) or (op == 162) or (op == 166) or (op == 168) or (op == 171) or (op == 173))
Return True if the operation is commutative
def opIsCommutative(self):
    
    op = self.get_op()
    return ((op == 144) or (op == 146) or (op == 149) or (op == 150) or (op == 151) or (op == 155) or (op == 157) or (op == 160) or (op == 161) or (op == 162) or (op == 166) or (op == 168) or (op == 171) or (op == 173))