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Hi guys and welcome back.

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Just a quick video to tell you about Booleans.

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A Boolean is a value that can be either true or false.

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And we can use that to make decisions,

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for example, using Boolean logic,

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we can tell whether a user's age is over 18.

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Or whether the user's character in a game

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has pressed the up arrow.

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Things like that are what we need Booleans for

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and they are everywhere in Python

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and in Programming.

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Let's learn more about them.

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Booleans are created by using comparisons.

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So, you can compare two things together

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to calculate whether two things

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are the same or different,

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for example, if you print five equal equal five,

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this is a Boolean comparison,

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five equal equal five.

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Notice that a single equal sign

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is used to assign a value to a variable.

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But two equal signs, one after another

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are used to compare two things.

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And what we're comparing here is,

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five and we're gonna check whether it is

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exactly equal to five.

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So, these two numbers here are being compared

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and we're going to get true,

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if they are exactly equal

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and we're going to get false if they are

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in any way different.

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So, if I run this here, you'll see

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that we get true out.

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As well as equal equal,

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you can use the typical maths operators

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such as greater than,

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to calculate whether a number is greater than

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another number.

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And there you get false.

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As a special case, you've also got,

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exclamation mark equal, which is used

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to tell whether two things are different.

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So, what this reads as is,

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is 10 different from 10?

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So, again, you'll get true if they are different

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and you'll get false if the are not different.

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So, here we should get false,

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because they are not different.

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Other comparisons that are available

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as well as equal equal, not equal

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and greater than are less than

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and greater than are equal to,

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or less than are equal to.

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And this is how you write them in Python.

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So, you can check whether something is

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less than one thing, whether it's greater than

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or equal to something else

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or whether it's less than

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or equal to something else.

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I'll say at this point,

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that you can use these operations,

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not only on numbers,

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but on any other value including lists,

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and tuples and strings and what not,

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but they can behave differently depending

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on what type of data you use them on.

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We're going to learn more

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and get more acquainted with how they behave

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in different scenarios, as we go along

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with better examples, of course.

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So, these are the comparisons

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and as well as comparisons, you've also got

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a few Python key words

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that you can use to calculate Booleans.

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One of the more confusing key words in Python,

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when you're talking about Booleans

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is the ease key word.

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So, here we've got two list,

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friends and abroad and they have

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the exact same elements inside them.

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You can print whether friends equal equal abroad

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and when you run this code,

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you get back true,

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because the equal equal sign,

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when you're talking about two different lists,

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compares whether the elements inside them

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are the same.

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And here, because you're comparing two strings,

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then Python can detect

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that these two lists are actually the same.

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However, a lot of new Python developers

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will try to do friends is abroad,

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which is something you can do in Python.

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But you won't get what you expect

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because you get false.

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That is because when you create a new list,

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Python goes and creates some space

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in its memory for this new list.

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The elements can be stored somewhere else,

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but the list itself has its own area in memory.

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Then when you create another list,

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it goes and creates another area in memory

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for this other list.

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The elements inside the list were created separately

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and they could be the same between both lists,

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but the lists themselves are different.

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And that is what the is keyword checks in Python.

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It checks whether two elements are exactly the same thing,

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not whether they have the same elements inside them

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or whether they are similar.

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So, again the is keyword is to compare

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whether two elements are the same thing.

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So, if you do friends is friends, for example,

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you're going to get true.

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If say abroad equal friends up here

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and then you check whether friends is abroad,

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you're also going to get true

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because you haven't created two lists.

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You've just pointed the two variables

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to the same list.

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And that again is what the is keyword is for,

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I recommend you almost never use it.

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You're almost always gonna want to use

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the double equal sign.

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All right, that's it for comparisons

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and this brief introduction to Booleans.

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Let's learn more in the next video.

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I'll see you there.