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Welcome back everyone in this lecture we're going to finish off our discussion of basic data types and

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data structures of Python by talking about tuples sets and booleans.

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They're all kind of minor smaller topics so we're going to link them all together in this one single

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lecture.

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So Let's first discuss each one and then we'll head over to the Adam code editor and check them allow

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OK we have tuples So what are tuples.

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Tuples are actually very similar to lists.

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However they have one key difference and that is immutability.

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So remember with Lisse you can mutate or change elements that are already inside of the list.

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Tuples pretty much operate the exact same way as far as an ordered sequence except that they're immutable.

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Once an element is assigned inside a tuple it cannot be reassigned.

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And the difference in syntax is that instead of using square brackets tuples are going to use parentheses.

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So here we can see an example of a tuple holding three items one two and three.

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Notice it looks a lot like lists except instead of square brackets we have princes there.

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Main difference here is immutability.

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So when you are objects not to be changed within an ordered sequence tuples are a good way to go that

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we have sets sets are an order collections of unique elements.

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So what do we mean by unique.

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That means there can only be one representative object of the same kind of objects.

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So we're going to see some examples of that later on in the text editor but just keep in mind sets there

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an order collections of unique elements and then finally booleans the last to discuss and booleans are

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just operators that lights convey true or false statements.

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And these are really important later on when we deal control flow and logic.

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So let's learn about these three data types tuples sets and booleans.

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Let's head over the atom.

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OK.

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And to start off by talking about tuples so tuples they look a lot like a list except they're going

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to use parentheses.

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So we're going to make a tuple of one two three and then I'm going to print out the tuple itself and

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you can use indexing just like you would for a list.

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So if I wanted to grab the first item in the tuple I would just say t of 0.

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So save this and run it.

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And here we have the entire tuple and then the first item in the table.

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And just like lists that can actually have mixed data types so we can have the floating point number

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a letter string.

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All that's fine tuples not going to complain.

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Remember with a list I could do some sort of re-assignment.

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So I'm going to show you that there an example.

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I'm going to say my list.

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Square brackets One two three.

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And let's just make the tuple again one two three.

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So a full list I was able to grab the first item in this fashion and then set it equal to something

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new.

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Now you're going to notice if I print out my list that it's not going to complain about that.

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So we already learned this from The Last Lecture.

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If I run this code now I get back new to 3.

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So I can easily do a re-assignment.

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That means lists are mutable.

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Let's try the same thing with the tuple though.

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So I'm going to try t of 0 set it equal to.

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So let's try to get this one equal to you and then I'm going to print out my tuple.

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See.

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So what happens when we try running this.

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You actually get back an error that says tuple object does not support item assignment.

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Remember this is a really similar error we got back when we were working with strings.

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So tuples are really similar to lists as far as slicing and indexing goes.

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But you can't do the re-assignment.

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So you typically want to use tuples when you want something set in position not to be edited by a third

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party user.

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So things like calendar dates are always going to come in the same order and you don't want someone

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to just come in and change the 7th of the date to maybe the tenth.

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So that kind of thing.

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Tuples are a good choice as we learn more and more about Python flask.

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We'll start to see natural use cases for tuples.

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Often beginners start using lists and then later on when they start dealing with other people using

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their code.

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They begin to graduate to using tuples.

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OK.

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So we discuss tuples and a some people call and tipples as well.

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Keep that in mind.

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Now we're going to talk about sets and booleans.

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OK so sets are an unordered collection of unique elements.

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I'm going to create a set by saying x is equal to set open in close print C's and then if I just print

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the X.

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You'll notice right now when I run it.

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Because the back and empty set.

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Now let's try adding an item to that set.

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So the way we do that is we say X add and then I'm going to add on the number 1 to the set and then

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let's print out the resulting set after that which is x.

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So when I run this now I get back this sort of notation it uses curly braces very similar to a dictionary

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except notice now there's no key value pairs.

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It's just items inside of the set.

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So let's add one more.

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In fact let's do this before we print.

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We're going to add two and then we're going to add three.

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Save those.

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Run this and I get back.

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One two three in my set.

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So set syntax wise is curly braces with each item separated by a comma.

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So what's the big deal here.

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Well let's try adding theory again and in fact let's added a bunch of times going to say add one add

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two and then add three three times.

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The key here remember is that sets are an order collection of unique elements.

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So when I try to run that I get back the exact same result.

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One two three because three is already represented because it's already the single representation of

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that unique element.

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So you can't be adding more representations of that same element and so that only takes unique elements.

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So that's how a set works.

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And because a set works this way you can easily get back the unique values of A list by passing it through

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the set function.

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Let me show you how that works.

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I'm going to create a list called 1 to 1 2.

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This is to make a bunch of repeated numbers here.

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So some of them are repeated some of them messed up.

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So let's go back and fill these in.

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There we go.

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So just create kind of a list of random numbers here.

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But make sure some of them are repeated so twos or repeated ones are repeated and so on.

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And then if you want to get back the unique numbers where you can do is you can say set passen that

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list and then print out that result.

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So we're going to say set my list save this and run it and notice now we get back a set of all the unique

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elements 1 2 3 4 12 and 21.

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So that's a really useful use case for the set function able to easily grab only two unique elements

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from a list.

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And later on we'll learn about more use cases for sets.

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Typically these are going to be kind of more advanced use cases.

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So right now as a beginner you won't really be using sets that often.

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Finally I want to talk about booleans sibilance we're going to talk about this in a lot more detail

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when we discuss control flow.

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So let's take a look at these booleans.

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Basically it's either true or false.

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So you can say a is equal to and then I have to make sure it's a capital T.

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In order for it to be the true keyword.

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So if I print out a here it's going to show me true.

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So true.

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Notice if I try a lower case t I end up getting an error saying something like true is not the.

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A truth is not defined.

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So you have to make sure that it's a capital T.

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In order for that true boolean and likewise there's a false Boolean.

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So if you want things to be false you can set B equal to capital F false.

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And the third one I wanna to talk about is a placeholder called none.

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So that's another special key word which are going to see it later on.

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But essentially you can use that as a placeholder for an object that you don't want to reassign yet.

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So these are booleans.

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True and False.

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And then none.

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That's basically kind of a special keyword which we're going to see later on in the course.

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We're not going to use it immediately but I just want to introduce it now since it's kind of similar

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to the booleans ideas.

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Now why are booleans useful.

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True and False.

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They're going to be useful when we start learning about control flow and we will only want certain blocks

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of code to execute when something is true or when something is false.

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Now we're going to learn about comparison operators later on.

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But basically those are things like is one greater than two.

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So if I print out the result of that I get back false.

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One is not greater than two.

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And if I do the reverse is one less than two and I run that I'm going to get back.

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True.

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So right after your exercise lecture It's coming up next we're going to discuss comparison operators

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in a lot more detail.

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So right now as far as tuples sets and booleans are concerned this is just an introduction to those

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terms.

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The actual implementation and use cases of those kind of things are going to be seen much further along.

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So I just want to introduce them to kind of close off this discussion on data types and data structures.

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All right I think we've learned enough so that you can get some exercise and testing new skills.

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So let's go ahead and jump to the next lecture.

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We're going to show you the quick overview of your exercise assignment.

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We'll see you there.