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[no audio]

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Friends here we are going to discuss about Sys Module. See

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basically Sys Module is used to work with Python runtime

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environment. I mean while running your Python script, if you want to

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interact with your Python interpreter then Sys Module is

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helpful. Guys, generally people will get confused whenever if they

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are discussing about Sys Module.

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See generally 'Sys' means we will feel it has a system.

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Yes, of course

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it is system, but it is not your operating system. Whenever

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if you are using Sys Module in Python it is helpful to get

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Python runtime environment on your system,

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not about your system.

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It is about Python runtime environment on your system.

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Right? Fine. Now,

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this Sys Module provides some functions and variables,

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you know, any module provide always some functions and

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variables or simply some operations, and these functions on

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the variables are used to manipulate different parts of the

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Python runtime environment.

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Let's say you are using Python 3.7.0.

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[no audio]

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To get that information you can use this module.

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[no audio]

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Right? You have different things.

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I will show you one by one, right? Simply assume that 'Sys' is

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used to get Python runtime environment details. And we know

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that, if you want to use any module, not only 'Sys', what is

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the first step you have to do? Always we have to import that,

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and to list out all functions and variables, and to get some

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documentation, these two are the helpful things. 'dir' of your

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module will give the list of operations or functions and

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variables, and 'help(sys)' will give the complete documentation,

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right? So we are at initial stage.

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Let me open once again my Python terminal, right by typing

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simply 'python'.

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Let me 'import sys',

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then 'dir(sys)', will you the list of

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operations or the functions which are there with your 'sys',

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and the variables.

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So by seeing all of these, you can't understand which is a

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function and which is a variable. Then how you can understand

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that? That's why you have a document here.

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So initially you are at initial stage, right?

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That's why, before going to use all these operations

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just have a glance once on your 'help', your document.

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Just go through this top to down. Just have a glance.

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Don't try to learn. Then somewhere

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you have see functions, right? Now,

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these are the functions.

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Let me go down, right. It will take some time.

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Just wait.

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Let me go down.

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Now, you have 'data', that means whatever you have here,

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they're are like variables.

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That's it. Now, you know, if you want to use variable from any module,

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you have to do simply, suppose

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let me take one of the variable called

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'platform'. So guys this is not your operating system details,

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'win32'. It is your Python software, which is installed on

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your host as a 32-bit.

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So on Windows I install my Python software as a 32-bit Python

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software. That's it.

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Let's say I have one more variable called 'version'.

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If it is a function you have to take parentheses.

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Right. Fine.

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Now, let me open a simple script.

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So let me open my 'Sublime Text'.

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So I am going to write a simple script using your Sys Module,

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right? So command line are helpful to know your documentation,

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right? But if you want to write a script just select any editor.

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I am selecting, suppose 'Sublime Text'.

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I am going to work with the Sys Module,

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so basics of 'sys'.

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'.py'. So guys, I want to use this module, then

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what is the first step

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I need to do? Import Sys Module.

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So you have seen what are the list of operations which are

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there with your Sys Module by running simply 'dir' of your

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'sys'. Right.

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So these are all the operations.

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Now simple things. See I want to display the version of my

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Python. If you remember you can find out that using

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your, from command line you can run simply 'python' space

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'-- version', right, or previously

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we had a discussion on Platform Module, in Platform Module

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also you have one of the operation to get your Python version,

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fine forget about all those things, simply using 'sys'

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also you can get your Python environment details,

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that is simply 'sys.version'. I am saving and running, see the output.

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Yes, you are getting. I want to get in terms of tuple. See that,

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you're getting, right.

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So either 'version' or 'version_info', both will give your Python

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information details.

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[no audio]

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Then let me comment these two things, these two are variables,

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right? I am going to take some more variables, suppose

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I want to know

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the modules which you imported to run your Python script,

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so for that in 'sys' you have 'modules',

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'sys.modules' will list out, simply you're not going to use

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them but simply we are seeing how many modules you are importing

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to run your Python script. As of now, you're importing only

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'sys', right. But see the magic what you are getting.

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See, these all are the modules, different modules

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you are importing to run your Python script.

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Actually, you are not importing. You are importing only 'sys'

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that is there in the very first, in output but remaining all modules

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by default your Python is importing to run your Python scripts. By default

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Python is also importing some modules.

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So we are able to see that information with the help of 'sys'.

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That's why we are saying that 'sys' is a module to work with

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your Python runtime environment, right?

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Not only that.

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Let me take one more thing, 'print(

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sys.path)'. So what is the 'sys.path'? First observe the

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output. You're getting some list of paths. See while running

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your Python script, your Python needs some libraries and modules,

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right? All those libraries and modules

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your Python is importing from all these paths.

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See, not only here, if you are good at your any Windows or Unix-like

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systems, right. See system is also depending on some paths.

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So these are the paths your system is using while running

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some scripts or programs on your Windows operating system,

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the same way while running Python script, Python needs some

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paths from which it's importing some modules. See by

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default, Python is importing some modules

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no, then from which location it has to import? That information

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is there in 'sys.path'. Now simply you can say that 'sys.path'

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is an environment variable for your Python,

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is an environment variable for Python.

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That's it.

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Fine.

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Okay, so these all, whatever we discussed just now, right, you

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may or may not use regularly in your real time,

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but the next thing whatever I'm going to write that you are

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going to use it.

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Right. What is that?

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Just observe here.

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See I'm writing simply

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'print("hello")', run the script, and see the output.

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Yes, you are getting your output.

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"Hello". Right.

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Now, what I am doing is, before your "hello",

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I am writing 'sys.exit' to stop my Python runtime environment,

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that means stop the script.

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See the output. You're not getting anything because actually

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whenever if you press 'Control + B', or whenever if you run your

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script from command line, something like 'python', your script

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name, you are trying to run your Python script, but what I

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am saying internally, inside of your script somewhere I am

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saying, "Please stop my Python",

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that is the meaning of this 'sys.exit'.

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So you are working with your Python saying that "Stop Python".

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So you are stopping your running Python script, right?

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So because of this 'sys.exit',

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your Python is going to stop your run, stop

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your running your Python script.

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That's why you are not able to get this output. By this line

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itself you are stopping, then you are not executing this

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line. Be clear. It will be very useful. While going forward

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I will use in different scenarios this 'sys.exit'. The simple

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meaning for 'sys.exit' is, whenever, if your Python identifies

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'sys.exit' simply you are abrupting or stopping Python

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script, that's it.

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Okay, and this is a function.

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So by default 'sys.exit'

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will give return code 0. If you want to provide any

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other than 0 return codes, you can pass your codes here.

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So how to use that code? We will see. For time being just

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assume that 'sys.exit' by default with zero as return code,

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and if you want to provide any return code, yes you can

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provide inside of your parentheses.

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That's why 'sys.exit' is a function.

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Okay.

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Okay, guys. Thank you for watching this video.

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