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Can you believe it?

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I hope I didn't put you to sleep, but we're almost there.

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We have one last main data type set and then we're done.

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I know.

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I know this isn't the most exciting topic.

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Trust me, this is the hardest part.

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When you're starting out and you're just learning these things without understanding, why do I need

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this?

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How am I going to build the next game?

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How am I going to build the next Netflix?

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How am I going to build the next coolest Apple app?

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You're looking at this and thinking, I just learned a bunch of theory.

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I feel like I'm in math class all over again.

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I know.

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Trust me.

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I went through this.

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I was a self-taught programmer as well.

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These are the Lego blocks that builds our foundation.

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Once we learn these, we can move on to new things.

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And you'll see that once you climb this little mountain, things become so much easier and you'll realize

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the power.

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When we start building these projects toward the end of the class where you're going to say, oh, all

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these blocks that we learned, all this frankly boring part is all going to make sense.

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So hang in there.

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It's supposed to be hard.

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It's supposed to be tough, but you'll see very soon why this is so powerful and why what we've just

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learned is going to allow us to build some really awesome things and create some really awesome programs.

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So let's finish off with the last one, the last data type, the last data structure that we'll see

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in Python, at least from the main ones.

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And it's called set and sets are simply unordered collections of unique objects.

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Hmm.

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Let's have a look.

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Let's create a mind set and my set we create with curly brackets like a dictionary, but instead of

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a dictionary, we don't have key value pairs.

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Instead, we just have values like one, two, three, four or five.

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That's it, that's a set we just created a set, but remember, the definition I gave you set is an

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unordered collection of unique objects.

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What does that mean?

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Well, if I print this and say my set and I click run.

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I get a set, but if I had, let's say, another five in here and I click run.

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It only returns the unique sets or unique items you see in a set, there's no duplicates.

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Everything has to be unique.

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So this fire just never gets added to a set, for example, you can add things to a set like my set

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and then I can say add and give it a value like one hundred.

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And then let's say I do my set dot ad and then give it to if I click, run here.

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I see that I was able to add one hundred, but two well, two wasn't really added because my said already

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contained that data.

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It's unordered.

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I mean, we've created one, two, three, four or five here, but there's no real order to it.

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There's no bookshelf in our memory space that is right next to each other.

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These are all over the place in memory.

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But a set is able to find them because they're all unique.

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So they're all in just one location in memory.

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So let me ask you this, and this is going to be a fun little exercise.

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If I gave you an array.

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And let's say this array contained, well, this right here.

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And I want you to return an array with no duplicates, so I want everything in let's say let's call

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it my list.

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And a programmer has already created this.

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OK, and then your task is to create or return a list or a collection that has only unique items.

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How would you go about converting this into a set?

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Well, we've seen this before.

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We have a set function and we simply wrap my list in that set.

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And that's printed out.

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I click, run.

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Check it out.

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We have formed a new set from a list.

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And I've removed all duplicate values, when would this be useful?

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Imagine if we had usernames, right, or email addresses where collecting email addresses on our startup

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page, but we don't want to have duplicate emails.

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We might want to convert this a list of emails to a set and remove any duplicates.

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So we're not sending emails over and over.

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So that's really cool.

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What about this, can I let's change this into a set, so let's call it my set.

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It's going to change this into a set.

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There you go.

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And then what if I wanted to access my set an index of zero?

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Hmm, set object does not support indexing.

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Well, again, you can think of it more as a dictionary in order to access a set, we have to grab by

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the item that's in.

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That's the key to getting the information from memory.

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The way we would check if something exists is we simply say, hey, is one in my set and we run this.

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And we get to.

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We can also do the length of my set and we get five again, nothing too crazy, but one, two, three,

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four, five.

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Remember, it only counts the unique things because this will never gets entered.

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It's a set.

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And alternatively, we can also convert this into a list.

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If I click run here, you'll see that I now have my set as a list.

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And then we can also do, let's say, my set daughter copy and actually copy my set into something,

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let's say new.

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Or new set, and then this will be completely different or a new copy, then this original one.

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So let's test this up, this new set.

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If I use a method that we may have seen before, which is my set dot clear, which as you can imagine,

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clears the set and I click run.

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I have that new set, but when I try and print are all set, which was my set, it's going to be empty,

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an empty set, but the true power of sets comes in.

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The next couple methods that I'm going to show you and sets have quite a few methods, but don't worry,

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most of them are quite similar.

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So let's explore that in the next video.