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In Python, or in any other language, you get the

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core set of functions. For example, the print

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function and the open functions are part of the

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core Python functions. You can just use them like

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that, and it's going to work. Now you have many

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built in functions. But in the end, what you can

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do with them is quite limited. If you want to do

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more things, for example, you want to create or

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you want to remove a folder, connect to a web

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page, send an email, etc, etc, you need to write a

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lot of code all by yourself. And this is going to

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take you a long time. Fortunately for you, there

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are many available libraries of Python modules

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that you can use. The Python module is simply a

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collection of plug and play functionalities to

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solve a specific problem. And there are so many

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Python modules that, of course, I won't show them

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all, and you won't be able to know them all. But

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here, I'm going to show you how you can import a

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module and use its functionalities in your Python

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code. And then you will be able to replicate this

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for each new module you want to use. And first,

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I'm going to also comment this. So now I have a

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lot of commented line. So this is just as if the

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file was empty. I'm going to simply do import os.

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And I'm going to run that. And you can see

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this is working. So we don't have any error. But

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we also don't have anything on the screen. Okay,

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so to import a module, you simply do import, and

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then the name of the module, and then you can use

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the module in your code. And best practice is, of

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course, to put it at the beginning of your

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program. So I'm going to put it right there. Okay,

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even if I have commented lines, I'm going to put

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it at the beginning of the program. In the os

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module, what is the os module. The os module is

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simply going to give you some new functionality to

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interact with the os, and for example, to create

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files, remove files, create directories, etc. And

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now let's use this module, so this os module to do

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something useful. Let's say we want know, to

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remove the new file here that we have created

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previously. How to remove that? What we can simply

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do is, I'm going to write the code if os.path.exists,

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we are first going to check if the

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file exists actually, before we remove it. new_file,

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I'm going to do os.remove with new_file.

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So this is a function from os and actually,

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you have a sub module named path. So os.path.exists

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is going to tell you if the file

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exists and return a Boolean. So if this is true,

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you go inside the if and then you have a function,

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os.remove, which is simply going to remove

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a file. Here, you can give the relative path like

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this or the absolute path like we did before. And

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because we use that multiple times, I can also

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create a variable, let's say file_name is equal to new_file

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and just pass that variable here, which is

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going to make it more convenient. Now let's run

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that code, and let's look at the file here. Okay,

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the file is gone, new_file is gone. Now if I run

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it again, you can see so the file is still gone.

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And we don't have any error because we first check

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if the file exists before we try to remove it. If

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you try to remove a file that doesn't exist, you

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are going to get an error. So well, as you can see

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that just the way of using a module. import name

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of the module, and then you can use module dot

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name of the function. And sometimes you have a

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module inside a module. So module, so module

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function, alright, and one thing you can also do

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is instead of using import os, okay, which is

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going to import all the os module, you can import

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specific functions. So if you want to do that, you

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can do from os import, for example, remove. This

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is going to import the remove function from the os

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module. And you can do from os.path import exist.

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Okay, I'm going to remove this. And now what you

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can do, you can simply use the exists and remove

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functions like this. So if you directly import the

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module like this. import os, you need to put os.remove,

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but if you do from os import remove,

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you simply need to just write remove like this,

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and this is also going to work and with this way

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you simply import two functions. You're gonna

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import any other functions from the os module,

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just what you need. And now well, basically how to

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find that information, how to know that you need

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to do os.path.exists, os.remove? Well,

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I'm going to say to you, you need to search that

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on Google. And that's what I do all the time,

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that's what every Python developer do all the time

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is to search on Google. And to easily search for a

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module, you simply type, Python, the name of the

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module, and then module, and you're going to get

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to page so you can get to that page, docs.python.org.

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Okay, and on the top, so you can even

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choose the language and make sure that you have a

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version that is at least Python three, and that

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corresponds to the version you are using, okay?

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And then you can see you have the complete

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documentation for os. Okay, so if I search for

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os.remove, you can see I have always let's

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remove here, and you have all the information with

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some examples, sometimes the parameters you need

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to give, etc, etc. Alright, now you know how to

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import and to use a python module in your program.

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And you also know where you can find a complete

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documentation for any given built in module. And

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of course, you're not going to know all the

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modules and all the functions that whenever you

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have a problem, you just make a Google search and

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you're going to see what kind of module you need

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to use what kind of functions then you can read to

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the condition so you can use that correctly.