def test_size(self): o1 = Order() with self.aRaise(InvalidOrderException): o1.size = 100 o1 = Order(dir=Order.BUY, size=100) self.aEq(o1.size, 100) #buy orders can only be 0 or positive with self.aRaise(InvalidOrderException): o1.size = -100 #sell orders can only be 0 or negative o1.dir = Order.SELL o1.size = -100 self.aEq(o1.size, -100) with self.aRaise(InvalidOrderException): o1.size = 100