ฝึกพูดภาษาอังกฤษด้วยเทคนิค Shadowing จากวิดีโอ: Python For Ethical Hacking & Cybersecurity Basic Intro

So now that you have an interest in cybersecurity, what comes next is usually the question of what kind of programming do I need to know?

So in this video, what we're going to cover is the Python

that I think you need to know as you're entering into cybersecurity.

This is an introductory course into Python for the purpose of cybersecurity.

I have tried to keep it as streamlined as possible to

keep you away from having to watch a six hour course on Python for cybersecurity

that is just full of stuff that I think you're not really going to need in the future.

So this is a beginner course.

And if you have any questions as you're going through it, please leave some questions down in the comments or you want to cover something more in depth,

please let me know because I don't know exactly what it is

that you guys want to know and what you want to learn.

And so be curious and then let me know so I can try to help you out.

So I'm regularly seeing videos on YouTube that says Python for hackers or Python for penetration testing.

And in these videos, they don't actually teach you anything.

So my goal in this course, in this video, is for you to come out with some understanding of Python, be able to write your own for loops,

be able to understand variables, lists, strings, and functions, and for you to come out with the ability to write maybe your own recon tool.

It will take some practice

and maybe you're going to have to watch this video several times in order to fully grasp these concepts.

But my hope is that when you finish this, that you will be able to come out with a knowledge of Python, modify exploits that you find online,

and maybe even write your own tools.

All right, before we dive into this course, I want to take a second and ask you to please subscribe to my channel.

I have said this before, I don't get anything from doing these videos.

I don't get anything from putting out these courses for you.

My channel is not big enough and so the one thing

that really keeps me encouraged in making these videos is when you guys comment and when you guys subscribe to my channel.

So please subscribe and with that let's go ahead and jump into the course.

I decided to go ahead and show you guys how to install PyCharm on your Linux VM.

If you have a Mac or Windows, it's really straightforward.

You just go to the JetBrains, you download PyCharm.

I'll have this link in the description and you'll click Windows, Mac, or Linux, and then you'll just hit download and it will automatically start to download unless you're on Linux.

So I have had to do this for several virtual machines that I've had.

It won't download.

And so what you have to do is right click the direct link and you'll copy link.

then you will you will go to your terminal

and you'll run a wget wherever you want this file to be saved so

if you want its own pycharm folder put it in its

own pycharm folder for me it is in my downloads

and you can save it wherever you want you'll hit enter

this might take a little bit depending on your speed

that you your internet speed

and then you're going to unzip it wherever you downloaded it with this command right here

and then it will unzip a bunch of files will come out

and then you will be able to cd into the folder

so for me i will cd into my downloads

because that's where it is and then i'll go into pycharm

and then i'll ls inside here and i'll go into my bin

and then this is the executable i want to launch in order to launch pycharm

so i will type in bash and then I will type in PyCharm.sh and it will automatically launch PyCharm for me.

So this is how you get PyCharm on Linux.

If you are wanting it on your Linux, I usually write everything on my Mac and then if I need to run the code over on Linux,

I will pull it over to my Linux machine and run it over here.

So with that, we will get started in the next section.

All right, we are ready to start our python course

so we're going to start out very simply with a string a string is a

sentence that is a data type

so we're going to have several different data types coming up

but a string looks very simple it is what i think of as a sentence in english so you just have

hello world a string is always going to be stored inside of quotations

so if we were to print this it would print right here hello world for us

and if we change it it's going to change along with us

so this is really simply this is a string

and we can store strings inside variables

which is going to be coming up in the next section

but first before we go on you will see sometimes

that you need a string on a new line especially

if you're going to export something into a csv file you're going to want things on new lines

and at the end of your string you can type something like this and then say hello world

number two and then we can print this and we have hello world

and hello world number two and if I wanted to get rid of

that space I would do it this way so we have hello world

and hello world number two another way to go about printing this would be like this so print print

and then we put our quotations and we say hello

and then we can add this like this hello world just like

that and now if we were to print it we have hello world hello world number two

and then hello world you see there's no space right here this is something

that i run into regularly and I just had happened the other day.

There's two different ways you can put a space right here

and I'm gonna show you the easiest way first is just to add a space right there, rerun it and now you have a space.

But I think it's helpful to know more than one way to do this

so you can add another quotation and put a space in there and add another plus sign.

So you can run it this way and you still have that space

and it's really important to know this right here

because sometimes you'll be running a for loop

and everything is just smashed together and you want to space in there

and you can add spaces simply just by doing this.

So what I'm showing you right now, you may be thinking this is not ever going to be helpful

and I wouldn't be showing it to you if this wasn't helpful

and it's something you're going to run into in the future.

So this is a very streamlined course and I'm showing you just what you need to know in the world of cybersecurity.

Now we're going to be covering something called a variable

and a variable holds the place of some kind of data that we're going to want to use later.

So we'll go ahead and comment this out

and on a Mac it is command and then question mark and so we'll comment that out.

So now if we run our program there's no output and we're going to look at a variable.

So a variable can be something like this, name, and then the name Jim.

This name is going to hold whatever is right here.

So this is our variable, which is going to represent the name Jim.

So if we come down here and we print, and then we type in name, and then we run this,

it's going to print what is stored inside this variable.

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When we look at variables, one of the things you're going to want to be able to do, especially in the world of cybersecurity, if you ever want to write your own tool,

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is you're going to be saving variables, only they're going to be input variables.

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So if we were to go like this and we say name equals input,

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and then we type what is your name, and then we'll want a space right here.

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So when we type in the prompt, it has a space.

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we'll comment this out and then we'll print name.

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So we're going to print the variable, whatever the user inputs here.

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So now we can say, what is your name?

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And we can say Tom.

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And when we hit enter, it prints Tom.

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And there's something else that's really cool that I use all the time.

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It's called an F string.

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And what you do is you add an F at the beginning of your string, but you can print variables inside your string.

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So we'll go ahead and put name inside here.

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And so we can say hello, and then the name.

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So we'll say, run this.

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What is your name?

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Tim.

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And it puts out hello, Tim.

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So this is an F string.

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This is something you're going to want to know this is something I use all the time

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and in the next coming up videos we're going to look at data types

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and how we can pull information out of a specific string

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and this comes becomes really useful whenever you run a script on a victim machine or on your target machine

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or your target server you'll you may get a lot of output that you don't really need

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and this is a good way to start extracting data.

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So we'll start that here in just a moment.

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Okay, it is time to draw out some information from our string.

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So what we can do here is we can save a variable

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and we'll call this variable name and we can put inside of our name tommy.

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So we have tommy here and let's say we want to grab just this m right here.

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What we can do with this is we can say print.

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We want to print our name

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and then we add some square brackets just like this and when you're running python it always starts at zero.

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So it goes zero one two And so that first M is going to be 2, just like this.

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And so if we run this, it's going to print that M for us.

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And just to show you, if we want to print the T, we would enter a 0 here.

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And this is one of the most basic ways to draw out information.

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And it's going to get a lot more complex as we go.

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But this is what the square brackets do when you see them.

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And when we start to tackle lists and arrays, these square brackets become a really useful tool to remember.

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So as we continue to go through this, I want to pause right here.

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And I want you to go ahead and play around in your own text editor and print some, make some print statements, make them on new lines,

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add in some spaces, make some inputs and actually practice gathering information

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and maybe have two or three inputs and have it print things back

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and forth and you have a little conversation with your text editor.

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So I want to go ahead

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and give you this challenge for you to go ahead

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and play around with the things you've learned so far and try and really ingrain this information into your mind.

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These are the foundations of Python programming and you need to know and understand how they work.

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You're going to notice is you can name variables whatever you want

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and I name my variables really poorly mostly

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because the programs I write I write for myself

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and I am not working with a team of developers

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but maybe you will someday and

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when you name your variables you can name them whatever you want

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and you'll want to make them names

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so other people can understand what is going on so

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if you look at some of the code I've written in

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past videos I do this right here I name everything like this

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and it is not really the best way to go about naming these

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so I'll name one guy one and I'll go guy two

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and he'll equal Bob and then I'll come down here

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and I'll print guy two and then I run this

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and then I have Tim and Bob you can you can name variables whatever you want.

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Literally you can go whatever I want and you can make this a variable

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and then you can come down here

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and you can print whatever you want right there and you can name variables whatever you want.

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So I would recommend getting in a good habit of making your variables something

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that you can recognize and it's a very bad habit

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that I have because I make my variables so that people cannot read what I have done.

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So this is something I'm trying to get better at, but I probably won't because this is a bad habit that has formed over many years.

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But I want you to have a good habit of naming your variables, something that you can understand and other people's can understand.

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So as you go through and work through your challenge, try to name your variables, different things that you will be able to understand in six months after

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you have written a program and you need to go back and edit it.

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Okay, I have created this little challenge here for you.

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If you want, you can go ahead and pause the video

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and open up your text editor and see if you can create this little program right here.

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So we want to one, create an input with a greeting.

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So just say, hello, what is your favorite food?

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Let them put it in and then and then take another input

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and say what is your favorite hobby and store

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that also in a variable

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and then we're going to print with an f string their favorite food

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and their hobby so if you want to give this a go you can go ahead

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and give it a try if not we will start it now

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so we're going to start out with create an input with a greeting So we'll just say print hello,

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and then we're going to take an input, but we got to save it as a variable.

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So we'll save this as food, and it's going to equal an input.

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And we're inside the input.

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We're going to have the question, what is your favorite food?

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Space.

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I see that we have a typo here on all three and then that's going to be saved as their food.

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Then we're going to say input

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and this is going to be we'll just save this as hobby

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and we're going to take in input and we're going to say what is your favorite hobby?

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Question mark space and then we're going to print with an f-string all of this together

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and we'll say print your favorite food is

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and then if you remember we need our f-string here

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and we should grab our curly braces

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and say food

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and your favorite hobby is curly braces hobby now

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when we run this if we did everything right it should print for us this final statement after we give these inputs.

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So we say run and it says hello what is your favorite food

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and we'll just say chips what is your favorite hobby running

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and it says your favorite food is chips and your favorite hobby is running.

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So this is a simple input form

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and it's going to print out with our variables

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that we have stored and this is a good practice because

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when you write a program for a tool maybe that you develop in the future, you are going to want to know how to do inputs.

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So that way you can take the input, save it in a variable, and then later do something with it.

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So later on in the course, I'm going to give you a practical example of taking input and then running it in a program.

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That is really helpful.

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And I will cover that when we are ready for it.

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All right, so we have covered the string so far.

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This integer is a whole number.

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So if we say int, we have a number of seven floats.

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We're not really going to use these a whole lot in the world of cybersecurity.

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They have a point within the number.

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So 3.14 would be an example of a float to date.

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I cannot remember a single time I have used a float in cybersecurity.

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Usually that's more towards data science or something of that nature.

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A boolean is true false.

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You will want to remember boolean.

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We'll cover these a bit in the future.

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When we do our while loops, we'll be using the true false.

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So these are some of the different data types.

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And just to get an idea of what these look like,

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if we save a variable and we make it a float and we say like one,

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two, three, and then we print this, it will tell us what we have.

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So we can come down here and we can say print

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and then we can put type and then we can put in our variable

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and when we run this it will tell us

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that we have a float and

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if we put in an integer it will tell us that we have an integer and then so on and so forth.

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We can do this with an

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and then we can also do this with a string

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and we can hit run

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and it tells us we have a string sometimes we will do something like this and then

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we have this saved as a string here and then

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when we go to add this to something else we can get an error

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and it's because we have a string and we'll be trying to add together a string and a

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integer and it won't work.

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So we'll go variable two equals three.

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And then when we say variable three equals variable one plus variable two, we're going to get an error.

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And it's going to tell us that you can you can't add these together.

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So this is one version of how these matter.

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another version of this is let's say we want to print

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and we say we have an integer right here

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and we want to add it to a string

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and we can go like this

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and we say 70 what do you think is going to happen it tells us we can't add these together

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but if we take this and we turn this into an integer, what will happen now?

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Now it works.

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So this is the difference.

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So this is an integer, this is a string, unless we declare it to be an integer.

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And you can do the same thing with floats.

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So I'm not going to cover those.

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And then what happens if we do this right here?

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What do you think the output will be?

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And the answer is 7070.

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So this is the difference between integers and strings and how they work with numbers and data.

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So if we wanted to, we can turn both of these into integers.

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And this is the last example.

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I promise I don't want to bore you with adding these together.

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And then we say enter and we're back to 140.

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So this is a little bit of strings, integers, and booleans.

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And we'll kind of skip floats because I don't think really need them

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but it's worth mentioning so you know they're here and with

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that we will continue on with our next challenge okay

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so we have these numbers here number one two three four five saved as num one

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and then num two

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and then num three what i want you to do is to write this to your console

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or write this to your text editor

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and then i want you to add this variable plus this variable and see what the output is.

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And then I want you to take the second number in num1, so it would be this 2 right here,

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and I want you to add it to the second number in num3, which is this 7.

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So your output should be 9.

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I want to see if you can figure that out.

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And then the third challenge is to take num2 and change num2 into a float and print the type

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to the console so that way the console tells us that it is a float.

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So if you'd like to go ahead and pause

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and give this a try you can do that now or we will go ahead and tackle this right now together.

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So what we are going to do just first is we're just going to print

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and we're going to say we're going to turn this into an integer

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and we're going to go and write in num1 and then we'll add

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this as an integer and then we will say num2

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and this needs to be closed off

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or we are we will get an error

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and this should print it for us

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so it tells us here is the total if we add those together

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and then the second challenge is to add the second number

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so we'll just take this just a heads up copy

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and paste and programming is always a bad idea because

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if I have a bug here I just now copied

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and pasted it and I have two of them but what we're going to do is we're going to take this

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and we're going to put in our square brackets and

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if you remember it says zero one so we're going to say one

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and then we're going to say one I guess I didn't really need this and then we'll print this

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and our output is nine so now we've grabbed the second numbers

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and then our third challenge is to change number two into a float

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so that it prints float so what we want to do here is just say print

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and then we're going to tell it we want a type

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and we want to print out the type of num2 and then above that we're going to just type in num2.

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You can do this two different ways.

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I'm going to do it this way.

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I'm going to say num2 equals num2 and we'll just go like this

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and we'll type float and we'll close this off and now

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if we print this it tells us it is a float

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and we will continue on with our Python course in the next section.

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Okay, we are going to do a walkthrough of if, elif, and else statements.

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So this is the instructions for the little program I'm going to write.

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But when I finish this program, I'm going to give you a challenge to do something similar on your own.

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So I'm only going to give one example here

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and you're going to need to pay attention and maybe watch this walkthrough twice and then go on and try the challenge.

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So the first thing we're going to do is if you are under five, you are a kid.

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So our if statement is going to first need an input from the user

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that is going to tell us what is their age.

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So we'll just say we have a variable

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and we want it to be an integer and integer and we want an input.

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and we're going to ask them, what is your age?

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Question mark, space, and we have to have that space, otherwise it's really ugly in the terminal.

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And then we're going to start our if statement.

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So we're going to say, if you, this person's, their input,

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which is their variable, is less than the age of five,

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then we want it to print that they are a kid

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so print you are a kid now one thing we want to do is

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if they hit the age of five we'll need an equal sign here otherwise I'll just show you

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if we say we'll need an else statement

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so this doesn't air out actually we'll just let it air out we'll say what is your age

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and they say five and we get no output because they,

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this doesn't include five, remembering that the computer starts at zero, and then it's going to stop at four.

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So if we want to include five in as you're as a kid, we'll need that the variable is less than or equal to a five.

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Now, if we put the five in here, it will print for us, you are a kid.

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So what we need to do next is we're going to type in elif

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because we're going to make an elif statement

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and we're going to say the variable is less than 15

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and the reason we don't have to worry about anything under 5 is

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because it will catch this if statement

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and then this whole program we write after this will stop

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and the computer will actually skip it

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so we don't need to worry about adding anything else in here

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and we can say actually if you are less than or equal to 15, then we are going to print,

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you are a big kid.

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And then for the final elif, we will say the variable,

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and we will say if it is greater than or equal to 21, and that's ugly and we will say print

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and we're gonna print you are a bigger kid

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and now we're gonna put in an else statement

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and in our else statement we're going to print anything that's over 21 we're just gonna print you are old

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so now if we run this and we rerun the program we run it

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and we say how old are you

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and we say three we get your kid

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if we say 13 we get your big kid

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if we say 18 we see you're a bigger kid and

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if we say you are 44 we get you are old now

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because we're going to be using this as a tool for us to be able to write tools

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and modify tools I'm not going to cover this because I think that it's not really necessary for cybersecurity.

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But if somebody were to run this and they put in the letter A, it's going to crash our program because the letter A is not a number.

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It's not an integer.

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So what we'd have to do is we would have to make this

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so that if they put this in and it was an A, it would print, enter a number, and then rerun.

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But we're not going to do that because it's not really necessary for cybersecurity.

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It's just something to be aware about.

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Now, what's coming up is your challenge.

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Let me delete all this and I will write up your challenge for you in the next section.

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Your challenge here is to take the temperature from the user

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and then tell them if it is less than 20 degrees you need boots

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and this is from the US so I'm running in Fahrenheit not Celsius

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and if it's less than 30 you will need a coat

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if it's less than 70 you will need a jacket

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if it's over 70 it is nice outside so take this input

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or take this information and make a program with if elif

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and else statements okay so here is how i would go about doing this i would take an input

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and it will say what is the temp outside and this is this will need to be an integer

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because we're going to be comparing this as a number.

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So we'll say if var is less than 20,

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then we're going to print, and you need boots. and we'll say elif

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bar is less than 30 print you need a coat

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and then we're going to use one more

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elif here elif

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var is less than 70

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print you need a jacket

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and then finally we'll do else and it's above 70 then it's nice out

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and we don't actually need to put anything in there

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because this is an else statement

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so everything that's above 70 will automatically print it is nice outside

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so when we run this if we put 12 we need boots if it's 22 we need a coat

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and if it is 65 we need a jacket and

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if it's 85 in my opinion it's perfect outside

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so this is the if and elif

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and the else statements we're going to be moving into for loops

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and later we're going to look at nested if statements

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and they'll look something like this if it's less than 20 and then And we can say if it is,

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if var is less than, we'll say it's actually, it's greater than 25.

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Then we can print you need boots.

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And then we'll print something like gloves.

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So nested if statements look something like this.

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and you can have nested if statements just so you're aware of it.

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So if we say it's 26, it will, oh, because we're hitting this one,

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we'll hit, we'll say this is 15.

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So if we say that the temperature is 16, we hit you need gloves and you will need boots.

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so this is a nested

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if statement we'll cover these a little more in the future

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i don't know how much you will need these nested

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if statements i use them every now and then

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so it's nice to know that you can run nested if statements

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but for now we're going to move on to our for

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loops before we get into for loops too far i want to show you why for loops are important

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and i also want to show you why lists are important

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which we're going to be going over here in just a

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minute after we get the basic understanding of a for loop so this is a program i've shown it before

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it don't worry about what it looks like it looks kind of complicated

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but it's really not what happens is you put in a repo

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that you would like to target on github to go and search for all of the usernames,

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passwords, and files that just shouldn't be made to the public.

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So in this case, it's looking for pass for passwords on GitHub.

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But what we have down here is a for loop.

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So this for loop right here, we have an empty list, which we're going to cover in a second.

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And it goes out to GitHub right here, and it will go through all these links

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everything you can click on

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and it's going to narrow it all the way down to the repositories

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and it will click this link

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and then it will click to it'll click the file

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and then it will click the raw then it copies this entire thing

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and it puts it into a text it puts it into a csv file

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and then checks for the word password so that's the program itself

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but what's important to remember is what happens is it goes out

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and it pulls all the links and puts them in a list.

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Then it goes through this for loop and it takes all of these

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and it says for every one of these items that is inside of the links, which is actually this variable that I have up top,

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it's going to do something.

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So for loops are very important.

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You can see I have another one right here.

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So for loops, we are going to need them.

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Lists, you are going to need them as well.

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And I just wanted to show you this

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because sometimes what happens is you'll be going through trying to learn something

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and I'm showing you something very elementary and you are like, why do I need to know a program that tells me to put on a jacket?

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This is all building up to something

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that is going to be able to help you build tools

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and more specifically if you're new just be able to read through exploits

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and be able to edit them

442

because you're going to need to know how to read python

443

and edit exploits as you grow in the world of cyber security

444

so here is a very basic for loop

445

and i'm going to show you it in a string because we've already covered strings

446

and what this all this does is we have our variable string right here that is holding

447

hello world and so the way the for loop works is it says for i in string

448

so this i right here is going to be another variable

449

that holds one letter each time the for loop runs this i is going to represent one letter

450

and in a list it's going to represent each item in the list

451

so this will run i'm gonna run it

452

so you can see what this looks like the way it runs is it goes for i in string

453

so it's going to grab the first letter

454

which is going to be the h and then it prints it

455

but the for loop is not over so it runs the loop again

456

and it'll grab the e and it'll print just the e on a new line

457

and then it goes through

458

and it runs every single time until it is out of things to run and then it closes the loop.

459

So this is how for loops work.

460

I'd like for you to go ahead and write out your own for loop

461

and maybe put something different in here and try to get an understanding of how it works.

462

And if we wanted this to print all of this together,

463

you would have to store this into a new variable and then print it outside the for loop down here like this.

464

and this is where we would print our new variable

465

and we're going to cover this in lists because this is something

466

that you will need to do in the future

467

so go ahead play around with the for loop write one get an understanding of how it works

468

if this doesn't make sense re-watch it

469

and hopefully it makes sense i know after teaching for loops to several different students

470

that for loops sometimes can be hard to understand

471

but they are really useful and something you need to learn

472

so we're going to be covering lists in the next section we're going to be looking at lists

473

and a list is something that is going to be useful

474

because we're going to be appending to lists all the time within our for loops

475

so a list can look like this my list equals square bracket and lists always go inside

476

of square brackets and we can say item 1

477

and then comma item 2 and then we can do an item 3

478

so we have our list here and

479

if we want to run a for loop through this list

480

we will say for I in in my list print i

481

and now if we run this it will run item one item two item three

482

so this is a list we will be using these in the coming lessons

483

and they will be helpful for you in the future as

484

you've seen in this program I have two lists right here and they are used regularly to append to.

485

So lists is something you will need to know.

486

So go ahead, make your own list and see

487

if you can loop through your list and maybe try and just print something like this later.

488

Just print the item two.

489

So you'll have item one, two, three, and then print number two and see if you can remember how to do that.

490

If you have forgotten, it would look something like this.

491

Print, and then we can say my list, and then we can put this in square brackets, and we'd say zero, one, and then we have a one,

492

and now we could print this, and we have one, two, three, two.

493

So that is going to be it for the list.

494

We're going to move on, and we're going to start using lists in a more comprehensive manner.

495

so we're going to try a while loop now

496

and the way we're going to do a

497

while loop is by using a boolean i like to set a variable

498

and then set it to true and then at the end of the

499

while loop i will set it to false

500

so the way this works is make a variable

501

and we'll just say variable actually we'll name it on that's a good way to name the variable

502

and we'll say on equals

503

true and then we'll say while on and we'll make a variable

504

and we'll just call it variable because I don't know what to name it

505

and we will take an input and we will say continue running while loop

506

and then we will put y we'll put a y

507

or a no so would you like the while loop to continue yes

508

or no and then we can say

509

that we can go do something like this

510

and then we can set a variable up here

511

and say i equals zero just so you can see how many times this is running

512

and then we'll say i plus equals one

513

and then this should just continue to run and then we'll put an

514

if statement say if the variable equals equals in then we'll say that on equals

515

false and this will kill our for loop so now

516

if we run this it'll say would you continue continue running the

517

while loop and we will say yes yes yes and then

518

when we say no it'll kill the

519

while loop I forgot to print I forgot to print our I

520

so that we could see this so now we can say

521

would you like to continue yes yes and you can see our variable every time the I the for loop runs

522

our I gets added to one

523

so our for loop has run now it says seven times eight times nine 10

524

and then when we're done we can say no and we can end it.

525

We are going to be starting functions

526

and just to be clear I have not pre-written any of the code we're about to go over

527

or mostly anything we've gone through in this course.

528

That's why you've seen me make mistakes and

529

so as we start functions i'm going to try

530

and make this a little more realistic for us so that

531

when we are thinking through functions

532

and writing code in the realm of cyber in the realm

533

of cyber security you can start to get an idea of how this can be used

534

so we're going to start with functions

535

and a function just calls something very specific that we want to happen

536

so we can just say we'll call it my function

537

and then the way your function is going to start is with a def my function

538

and then we close it off like this

539

and then down here we want our function to do something very specific

540

so we can say print and then we can say it worked

541

and the way a function gets called is usually somewhere further down inside the code something happens

542

and it triggers this function back up above it for it to actually do something

543

so what would happen in order to call this is we would just say my function now

544

when we run this

545

when the computer reaches this right here this closing bracket right

546

here I usually like to think of this as the call sign for the function.

547

So if we run this, it's going to print it worked.

548

And this will become more clear as we write more of these.

549

But this is the basic concept of functions.

550

And one thing we can do with functions is we can pass through variables.

551

So we can say something along the lines of I.

552

And then we can say I.

553

We'll make it a different variable we'll say variable equals i plus three

554

and then we can say print

555

and then we can say we want to print our variable

556

and so in our function we can pass information through like this

557

so when we say my function we can now say input

558

and then we can say what would you like to add and

559

because this is a string we're going to need to make this into an integer i guess we can go

560

and make it an integer right here and we can say int

561

and then we can close this off now

562

when we run this it's going to ask us what would we like to add

563

and we can say three enter and it'll say three plus three equals six

564

so this is a very basic function

565

so we take some kind of input right here this is where we call our function

566

so now this function is being triggered

567

but we want to pass something into our function some kind of variable

568

or some kind of information that we've grabbed somewhere else

569

and what happens is it can now use this inside the

570

function this you may be thinking like in what case would I possibly ever need to use this

571

and so I'm going to just show you my github dumpster diving tool once again

572

that I've used multiple times on this channel this right here where it's grabbed a repo.

573

I call this function and it's going to loop through to see every single file inside of the repo.

574

Is it a Python file?

575

Is it a JavaScript file?

576

Is it an XML file?

577

And what happens is when I pass this repo through,

578

it now is able to use this variable that has come from somewhere else inside this function.

579

And then I do the same thing up here.

580

I pass through a variable inside of a function.

581

So this is really important to know and you will use it.

582

And we're going to go ahead and give another example.

583

And actually, before we give another example, I want you to try and write your own function and see if you can get it to take an input.

584

So let's take the input and make it the first letter of your name.

585

So I'll write out the instructions.

586

You want the, we'll say first letter of your name and you want to take this as an input

587

so we'll say input and then you want to call a function

588

that adds your first letter to the rest of your name.

589

So here's your instructions.

590

You're going to make a function and then it's going to take a variable

591

and that variable is going to be the first letter of your name

592

and then you're going to add that to the rest of your name.

593

So I hope this makes sense and I'll go ahead and walk you through what this would look like.

594

So we'll go def my function

595

and then we are going to call this function we're going to pass through let's use i as our variable

596

so that stops giving us whenever this is giving us an error

597

and i can't stand looking at it i type in pass

598

and that will not give us the error and we'll come back

599

and delete that in a second and we're going to call my function

600

and we're going to take another input and we're going to say what is the first

601

letter of your name question mark now we can delete this

602

and we're going to come back up here

603

and we're going to use this and we're going to say

604

that my function and we're going to take this input

605

and it's going to be a pass through as i and so down here we're just going to say

606

my first name is Ryan, so we will say I, we'll call it the variable equals I plus,

607

and then we can put the rest of this inside of a string, and we can say something like this,

608

and then we can print our variable.

609

So when we run this, if I put an R in here, it'll print out my name

610

so I hope you're able to figure this out maybe try

611

to come up with another way to write a function

612

and practice writing functions and see if you can get the hang of it

613

and in the next section we're going to go over something

614

that will show you how this can be really helpful in

615

building your own tool okay I hope you have played around with functions

616

and you are now ready to try and become a little more advanced and we're going to try and

617

gear it towards cybersecurity now and I hope you're familiar with maybe the in map scan

618

and some other tools so we'll just use an in map scan right now

619

and we'll just say like we're going to call a function

620

and we'll call it in map and this is going to take a variable

621

and we'll actually call it the IP

622

because we're going to take an IP address and the way I like to run my in map scans is with the,

623

they'll look something like this, in map dash a like this,

624

and then we're going to pass in the IP address, and then I like it to be verbose.

625

Now, in order to get this to run, we would have to import a module called OS, but we're not ready for that.

626

So, this is just to show you how the functions will work

627

and so I will wrap this entire thing inside of curly braces I got dashes in here

628

that shouldn't be there I don't know why I did that

629

and then we'll wrap this inside curly braces this is not supposed to be inside curly braces

630

that is supposed to be inside of quotes we'll make this in f string

631

and we'll say our variable equals instead this would be an os command

632

if we were actually going to run this in our linux machine

633

or windows whatever you choose to use as your hacking vm

634

and now what we do is we'd come down here

635

and we would say something like in map to call our function

636

and then we're going to take an input and we're going to say what ip would you like to scan

637

and then right here we are going to print running in map scan against and

638

then we will put in the IP address

639

and this will need to be an f string

640

so the way this sorry that will not be the IP

641

that will be against the variable so it will tell us

642

that it is running the in map scan right here okay

643

so when we run this we can say what's who would we like to scan against

644

and we'd say 192.168 point something point something else then we run this it'll print running in map scan against

645

and then it gives us the output right here

646

so this would be a way that

647

if you were trying to write your own tool to automate

648

your recon this would be one of those ways you would use a function in order to automate your recon

649

and there's a lot more you can do with this ip address

650

and you could pass it into multiple different tools

651

and then you have written your own tool

652

so this is how we can use functions in cyber security

653

that are really helpful for us and And whenever you're going for a certification, it'll be really helpful for you to be able to read through functions and maybe modify them,

654

especially in exploits because vulnerabilities and exploits change over time.

655

And you will need to be able to change

656

and modify different exploits that you come across on Google in order to gain access to a machine.

657

Before we end this course, I want to give you a little bit of an introduction into making your own tools.

658

And then I want to challenge you to add to this recon tool that I'm about to show you.

659

And you can start to build your own tool for recon.

660

And it'll help you remember the Python code that we've gone over so far in this course.

661

So I've gone ahead and connected to Hack the Box and launched the Box Devel.

662

Devel and so I want to just show you what OS system does

663

so we'll import OS system you've seen this before

664

and this is just our operating system it just means we're

665

going to be able to tell our Linux machine to carry

666

out commands the exact same way you would inside of a terminal

667

so we're going to make a function and we're going to call it recon

668

and we're going to pass through an IP address really

669

if you remember this is just a variable

670

that we're going to be passing through into the function

671

and then we're going to call our function down here

672

and we'll just call it recon and then we're going to ask for an input

673

and then we're going to say what ip would you like to scan

674

and then we'll put a question mark and a space there so that way it's not all smashed together.

675

Now inside of here what we can do to make this program run our recon

676

and automate it for us is we can type os system

677

and then we can put in here we're going to make this an f string what we want to do.

678

So we're going to run an in map scan

679

and we're going to run it on all port

680

or we're going want all outputs we're going to run it on all ports

681

and just in case it is blocking the ping we'll put the p

682

and you don't have to put this in here it's optional

683

and then we are going to put in the ip address

684

that we run through and i really like to run everything as verbose so this

685

when we run this you'll be able to see it'll say what ip would you like to scan

686

and i'll put in the ip address

687

and it will now start the scan for us

688

so this is the same thing we would see inside the

689

terminal we're going to see port 80 port 21 is open

690

and at the end of the scan it will tell us everything

691

that has happened on this scan now you can add to

692

this we'll stop this you can add to this same scan

693

when it gets done running the in map scan you can come down here and maybe you want to

694

look for different directories and so you could go os dot system and we're going to make an f string

695

and we can add in maybe we want it to run derb

696

and we want it to run on the same ip address

697

that we've already passed in

698

and it will now launch this right here as soon as it gets done with in map

699

and the cool thing about this is

700

if you have your own recon tool set up you can go ahead

701

and run the program send over the ip address

702

and then you can leave and it will automatically run your recon or maybe

703

while your recon tool is running you can do other more manual enumeration maybe it has port 80 open

704

and you see that real quick with the in map scan

705

and you want to start looking at what's on port 80

706

and it will run your in map scan it will run your durbuster for you

707

and maybe you want to run wfuzz

708

or maybe you want to run sublister i want you to go ahead

709

and start off with what i have given you right here

710

and you can add to this tool with the information that you have learned so far

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