[SOUND] So let's use our new found date time abilities to make

an app that will ask us math questions and time our answers.

We're gonna keep it pretty bare bones, but let us leave a place or two for

improvements.

If you haven't watched object oriented Python yet,

you'll probably want to before this video, so you won't be lost.

All right.

Ready?

Let's get started.

Okay. So

let's create a few classes that'll make it easier for us to create and ask questions.

Our app is just going to ask addition and multiplication questions.

So, our classes should be pretty simple.

I'm doing this in a file called questions.py.

So let's make a class Question and it's gonna have two attributes.

Answer, which is None and text, which is None.

I'm actually going to leave the class right there.

You would think I'd add more, but I want these to be very simple.

I want them to have a very simple API and

I don't want them to be crazily overextended.

You could definitely add some more to this to make them simpler or

to make them a little smarter if you want.

That's completely up to you.

So now let's make a class called Add and

it's going to extend question and I'm gonna override the init for it.

And it's going to take two numbers and so

we're gonna set self.text equal to this string format and

we're gonna stick in number one and number two.

And self.answer is going to be the actual value of num1 plus num2.

Okay.

So let's do the same thing here for multiply.

In fact, I'm going to copy this and

what we're going to do is we're going to change this, I'm going to put in an x.

You could use the time, the, the star, you could use a unicode time.

You can use the word times, whatever you wanna do.

So the only thing different here is how we calculate stuff.

I think this was pretty quick.

I think this was worth it, but let's test these out.

So let's come down here to our workspace and

let's do from questions import Add.

And we are going to do add1 equals Add and

we are going to pass int numbers, so lets do five and seven.

Okay.

If we look at add1.text, we get 5 plus 7.

And if we look at add1.answer, we get 12, which is right.

That's pretty awesome.

That's, that's what I wanted to do.

So before we move on and wrap up this video,

let's actually go ahead and do our quiz.

We'll do some planning on our quiz.

So New File, we'll do quiz.py.

At this point, well we're gonna have a class.

Right?

And we're gonna want to be able to store and

hold onto all the questions that we have.

So, our questions is gonna be an empty list.

Okay.

So cool.

But oh, wait.

So, if we're gonna use questions, we're gonna have to import them.

So we need to do from questions import Add, Multiply.

So we've got both of those.

We're also gonna wanna track how long it takes to answer these things, so we need

a start time and an end time and we're gonna wanna build these things randomly.

So that means, we're going to need to import datetime and import random.

So you notice that there's a blank line in between datetime random and questions?

That's because my local imports, I wanna have this, this little bit of separation,

just so I can see, like, okay, these are top level right here.

And these are my own custom ones right here and so on.

By top-level, I mean like built into the standard library.

You don't have to do this, but it's a good habit.

All right.

So when we initialize our quiz, we're gonna want to generate some question.

Right?

So let's, I don't know, we could probably do that indefinite.

And so let's just say, generate 10 random

questions with numbers from 1 to 10.

And then we'll say, add these questions into self.questions.

Okay.

Pretty simple.

Let's add a new method here called take_quiz.

And I think this is gonna be the method that actually, like asks the questions.

So, let's see.

Log the start time and ask all of the questions.

And log if they got the question right and

log the end time and then show a summary.

Okay.

This makes me think that since we've got this, this ask all the questions

it makes me think that maybe we should have a method that asks the questions.

So let's call it maybe ask and it'll have a question.

But you know what? Before we do that,

we'll put a pass in there, just to let these things pass.

Let's go up here and add an answers list.

And this would be what stores, whether or not they got a given answer right.

So we can go look, we can go okay.

Question number six, which has the fifth index and

answer number six which again, has the fifth index.

What's the question and what's the was the answer they gave true or false?

And that way we can go, oh, you missed question number five.

Here it is again.

Not something we're going to build, but something you could add if you wanted to.

Okay.

So, ask, what are we going to do here?

So, I think we should log the start time, because it might be a neat stat to show.

Again, not something I'm gonna write, but something you might want to add to show

how long it took them to answer each question.

So they can go, oh,

multiplication questions take me longer than addition questions or whatever.

We want to capture the answer.

[NOISE] We want to check the answer.

We want to log the in time.

So how long it took them to answer that question?

And then if the answer is right, send back true.

Otherwise, send back false and

let's send back the elapsed time too.

So that way, we've got back true or false and we've got back, you know, oh,

ten seconds or five milliseconds or, or whatever.

Okay.

And then I think,

the only thing we are missing is a we've talked about having a way to show summary.

So let's have a function that shows the summary print or, sorry, a method print.

Write how many you got right and the total number of questions.

So, you know, that'll be like five out of ten and

then print the total time for the quiz.

So, you know, that'll be like 30 seconds.

Okay.

So, I think that gets us in a good spot and we'll come back and

build the rest next time.

All right.

Well, we have two good classes for asking questions and quite a bit of planning.

Feel free to try and finish the app from here if you want.

I'll show you my solution to it in the next video.