def test_infix_to_postfix(self): myExp = 'a+b*(c^d-e)^(f+g*h)-i' myExp = [i for i in myExp] myStack = stack.Stack(len(myExp)) # create a stack result = stack.InfixToPostfix(myExp, myStack) resultString = result.infix_to_postfix() expectedResult = 'a b c d ^ e - f g h * + ^ * + i -' self.assertTrue(resultString, expectedResult)