Alright, thanks for completing that exercise and also thank you for hanging in there with me up until this point, I know the fundamentals of Python are not the most exciting part, but they are an important building block as you move toward more complex machine learning analyses. So right now we're going to move on to including variables in that format function, like I alluded to in the previous section. So here I have a piece of text that I'm trying to print using the format function that's showing me price, EPS and a PE multiple. And right here I have a space to define a variable P and to define a variable EPS. So I'm going to go ahead and I'm gonna give that P a value of 220 and I'm gonna give the EPS a value of 10 as if we're looking at a stock where the price is $220 and the earnings per share is $10. Now I'm gonna complete this line of text down here, and since this first set of curly braces is price, the second set of curly braces is EPS. And the last one is the price to earnings multiple. I'm gonna input these variables in my format, parentheses in that order. And instead of writing 220, 10 and then two 20 divided by 10, I'm just gonna put the variable P and then a comma the variable EPS in a comma, and then I'm gonna divide P by EPS. Now when I execute that, it's going to neatly put these all into one output. And the really nice thing is this shows you how you can use code to, to give a value to these variables and then input that dynamically into your output. So if I wanted to, I could change this definition to what do I wanna say, 22 times 10, or if I had some sort of an algorithm that was determining the price of that stock. So now I can hit shift enter to execute again, and it still goes all the way through. You can see that my price is 220, this division equation is working correctly. And that's how you can start to build a little bit more complex pieces of code is by using variables and using format to input those dynamic values into an output.

So you are not limited to using numerical values when you define these variables. So with P, I've used an equation 22 times 10 EPS is a numerical value, but I could create let's say M for our multiple and I could set that equal to an equation involving two variables, so our P and our EPS and now down here in my format function, I can change that equation to simply M and execute it and it's going to give the same exact result. Or alternatively, If I wanted that to be text, for example, I could set that using text and I could set this using text.

I can't do an equation between two pieces of text, so I'm gonna go ahead and change that to 22, and now these pieces of text will flow through my format. If I execute this code cell, I'm gonna get the same exact result. The difference is that now because these are text variables, I'm not gonna be able to perform the same mathematical operations between them, but I just do this to show you that you can define your variables as many different kinds of data. I want to give you one final piece of advice before we go on to the exercise for this section, and that is to use informative variable names when you're creating new variables. So here is an example of uninformative variable names. We've just named these variables B, C, D, A, and then down here you can see some sort of a formula is happening. It's not obvious what's going on. If I've never seen this before, if I wrote this in the past, I might look back on it a few months later and be confused about what it's about. Or if I'm giving it to one of my coworkers, it might be difficult for them to understand at first glance without me being there to explain it to them. So the code will work correctly. But because of these uninformative variable names, I might run into some problems down the road. Instead of that, if I were to give these descriptive variable names, now all of a sudden you can recognize this as the compound annual growth rate formula. And if I write it now and I don't look at it for six months, I'm gonna come back and I'm gonna immediately recognize that this is kegger. And if I send it to one of my coworkers, they're going to immediately recognize this is something familiar. I know what's going on here. Now if I execute this, all of the code is gonna work exactly the same. But because I gave these informative variable names, it's much easier for me to understand down the road the logic of my code. And it's much easier for other people to very intuitively understand what I'm coding.