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[no audio]

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Friends here

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we are going to discuss about comments, 'Comments of Python'.

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See before telling about comments

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let me open my terminal, right. So guys still I am trying to

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work using 'vi' or 'vim'

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editors, right. From command line

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I am using 'vim' editors.

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[no audio]

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Let me write simple Python Script first. Suppose

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I am going to write 'usage_of_comments

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[no audio]

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.py', any Python program or script.

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So here I am going to explain how to use comments.

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Right. So guys first thing, comment is nothing but, suppose you're

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writing some Python Script

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just assume you have some thousands of lines,

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[no audio]

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right, and to understand

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what is the purpose of your Python Script or

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Python program

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you have to go with each and every line and you have to understand,

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I mean suppose some third person.

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So instead of that

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you can write somewhere some comments,

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some lines representing that, saying that what is the purpose

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of this code. Suppose

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let us say first of all I am going to write some simple

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Python program, some 'a=4', and 'b=5',

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and then I am finding 'result=a+b', don't worry

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guys how to write this program,

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okay, while going forward we will learn how to write. Now

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I am trying to print, right, "The addition of and is:",

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this is the "".

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Just I am printing this,

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okay. Let me save this and write it, and let me run this. We'll

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check it whether we are able to get the output or not.

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Yes, we are getting some output, right. Now see because this

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is very simple program by seeing that you can understand

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that, yes we are defining two variables and we're finding the addition

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of those two variables, and we're printing. But instead of

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that I can write some comments somewhere.

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So I am writing.

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'This is a simple

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arithmetic calculator and implemented by suppose'

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[no audio]

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and when it is implemented, let's say suppose some July 2019,

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and what is the 'Version' of this code,

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let's say this is "V.1.0".

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If you observe guys, these lines are not your Python program

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lines, but these are something like comments to give some

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information about your Python Script or Python program.

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That's why if I run this program, right,

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let me delete that last,

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yeah, now let me save it,

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and if I try to run your script you will get an error.

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"This is a simple automatic calculator" is 'invalid syntax'

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because that is not a valid syntax.

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Actually, this is not the Python program line.

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So you are writing something to give information about

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your script to the third person, right.

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So those lines are comments, and while running your Python

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program if you want to skip these lines, these lines you have

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to write, each and every line you have to start with the '#'

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symbol so that all lines are commented out. Your Python, while

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running your Python know your Python won't consider

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these lines are as your Python's program lines and simply

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your Python will skip these lines. Even though if you write this type

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of lines, thousands of lines in your program,

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your Python won't consider these lines as a Python Script

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line, and then simply it will skip those lines. And your Python

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program starts from here, 'a=4', 'b=5', 'result',

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and these four lines will execute,

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[no audio]

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right. Now, let me save it and run it.

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Oh, man.

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[no audio]

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Let me save this. Now,

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I am going to run. Now instead of getting an error

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you will get output. That's it.

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Right. Fine.

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So guys now you have to understand that to comment a single

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line you can use '#' symbol,

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right. Even if you want to comment some thousand lines for

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each and every line before starting your line

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you have to write '#' symbol.

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Let us assume that you are having suppose some 100 comment

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lines, and they are in sequence.

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Right. So to comment your 100 lines what I have to do? For each

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and every line I have to start with '#' symbol, but I am

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the lazy person, right, now I am going to use some shortcut.

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Whatever the lines you want to comment, all those lines

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you can write between triple quotes. Those triple codes may

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be single or double. I can use either single quotes three

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times or double quotes three times.

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Now, this is exactly equals to your placing, if you want

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to comment all these four lines, how you're commenting? By

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placing '#' symbol on the starting of your each and every

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line. Now instead of that you can simply place your commenting

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lines, comment lines between these quotations. These are triple

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quotes, either single triple quotes or double quotation symbol

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three times, right. Now,

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let me save this,

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and run that, and see the output. Before going to run

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let me do one thing.

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[no audio]

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I am going to see your script.

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This is your script, and I am going to run that.

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Perfectly working, means your Python now is skipping these lines,

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and these lines are commented out.

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Okay. So guys comments are two types - single line comments and

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multiple line comments.

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So single line comments, you can comment with the '#' symbol,

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and multiple line comments, in case if you have sometimes

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you know, or some sequence of lines, some 100s, or 10s,

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or some 50 lines, right, or maybe two lines also, you can comment

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with the triple quotes as well. So multiple line comments is triple quotes.

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So and remember that it may be single quotation three times

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or you have to start with three double quotations, and you

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have to end with the three double quotations. That's it.

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[no audio]

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Okay, I hope it's clear.

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Okay guys, thank you for watching this video.

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[no audio]