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Welcome back.

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Let's talk about the topic of formatted strings.

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Up until now, we've just written simple strings, but we want a program that's dynamic, that's static,

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let's say we have a Amazon page and we're working on Amazon, actually.

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And when a user logs into their profile while we want to display their name or what they have in the

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cart.

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In that case, we don't want to just hard code and write every single user's name like Andre or another

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user Jo, and write every single name in the world, no.

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Ideally, what we can do is have something dynamic where let's say it's a profile page and we simply

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use the name variable and we display that on the page.

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Now, this name variable should equal whatever the user's name is.

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And this is something that we can grab from the database again, something that we'll talk later on

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in the course.

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But let's assume that in here when we do equals we're going to grab some user information.

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Which will be the name and this name for now will be John.

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All right, let's go, Johnny and this Johnny we want to display on the profile page.

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And we can do that with formatted strings.

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We can simply do something like print and then say name.

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But we also want to greet that person, right?

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So let's do hi.

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And then plus name, I remember to outerspace, if I click run, I get Hi Johnny.

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But as we get more and more information, let's say we have age and Ajani is 55, if I wanted to extend

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the sentence and I want to say you are and then add another plus, make sure we add a space in here

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and then add your fault.

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Ron here, hmm.

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All right, we get to type air must be stirring, not into.

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Oh, boy.

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All right.

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So we have to convert this into a string.

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So remember, we can do that like this.

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And then if I click, run.

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Hi, Johnny, you are 55 year old or years old.

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All right, that was a little cumbersome, but we're making our Amazon page dynamic, we can grab different

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information from the database and we'll have in a string something according to the user.

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But there's a better way of doing this.

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And with formatted strings, all we need to do is add an F at the beginning.

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And this F at the beginning is going to tell Python, hey, this is going to be a formatted string,

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and instead of doing all this plus and name and all this stuff and doing the start to convert the type.

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We can simply do something like this, let's remove this and simply do Brackett's and say name.

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And then again, remove all of this.

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And say age, so I'm going to say hi name, you are eight years old, and if I click run here.

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You see that it still works.

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This is a new feature of Python three by adding F to the beginning.

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It's saying, hey, this is going to be a formatted string and I want you to just make these variables

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available.

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Strings inside of, well, this string.

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How much cleaner is that?

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Now, although this is nice and clean and this is my preferred way of writing strings before Python

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three, you didn't really have this.

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So in Python two and mind you, this works in Python three as well.

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As you can see, we had something different to accomplish this.

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What we had was this idea of a DOT format.

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And DOT format, so let's remove the F here, is going to do the same thing for us.

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We do a bracket here and then we say, hey, we want Johnny.

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And age of 55, and we can just remove these variable names.

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If I click run here.

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Hmm, I get an error and you have to be careful here, Daudt format works on strings, but you can see

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over here that we did it outside of the brackets.

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And what it's doing is saying, hey, Ron, the format action on this print.

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But print is not really a string, right, so you have to make sure that we move the brackets to the

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outside so that we evaluate this piece of code first.

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So the string is going to get formatted and then we're going to print.

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Hi, Johnny.

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You are 55 years old.

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So that works the same way, but what if we wanted to use variables because right now we're just doing

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this by order.

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So whatever comes first gets filled in first in the brackets.

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Well, we can do something like name.

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And H let's see, can we do that, let's run.

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There you go.

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That works the same way.

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What if we had a specific order, maybe we want this to be H and here to be named?

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Well, we can mix those around.

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We can say one here and zero here, because in computer science, we always start counting from zero.

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So this is zero.

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And this is one.

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If we had something else in here, let's say a third variable, then this will be.

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So if I click run here.

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All right, everything is upside down.

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Finally, I can just create my own variables if I want to do so, let's say hi, let's say a new name

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equals.

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Sally and then Age of Sally is going to equal, let's say, one hundred, Sally is very old.

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Now, if I do zero, let's say on one here.

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OK, quick run.

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So now we'll actually get an air tuple index out of range.

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Now, we haven't really learned about tuples and ranges.

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And this is a little confusing, but a bit of a trick here.

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We want to make sure that we add now because we've given.

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The actual variable, a value we need to actually say new name here.

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And here will be H.

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So that if I click run.

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There you go.

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Hi, Sally.

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You are a hundred years old.

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As you can see with DOT format, things are a little bit more complicated, you'll still see this and

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all python to.

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Code still uses the format and you'll see a lot of Python three code bases that still use DOT format

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because some people prefer it.

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But I would argue that the F.

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At the beginning of a formatted string is the way to go because, well, it just makes things so much

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easier, right?

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Nice and clean, nice and easy.

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So I do recommend that you use the formatted string with the F in front and for short, we usually call

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this an F string.

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All right.

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I'll see you in the next one.

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Bye bye.