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[no audio]

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Friends, here we are going to

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do one simple practice with your for loop.

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I mean, I'm going to write a simple Python Script. The requirement

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is, read a string and print characters and their index values.

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I mean, suppose if you run your Python Script, it has to ask

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'Enter your input'. Then enter some input.

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Let's say I am going to enter input as 'python'. Then it has

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to give output as, in this format.

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'p-y-t-h-o-n'. At the same time

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it has to print the index value of your letters

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or characters in this way.

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[no audio]

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Right. So, guys before going to watch the next part in this video

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first just pause this video and try to write your script

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to read some string and to display your output in this way.

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Right. Just, you just give your try, then come back and watch the

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remaining part, right?

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Okay, but as of now, I am going to write, you just pause it and try.

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script from your side.

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Okay. Let me save the code as, I mean script name as

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'read_string',

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[no audio]

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then, '_print_with_index_values',

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[no audio]

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'.py', right. See, you know, if you want to read a string

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what you have to do?

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Let me take, 'usr_str'

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I am taking, equals to, I need to read a string. You know,

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if you want to read a string you have to use 'input' syntax,

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right? So, what I am doing is "Enter your string :".

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[no audio]

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Okay. Assume that user is going to enter anything,

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any string, right.

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Now, what I am doing is, see here

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'for each_char in usr_str'

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let me print first all characters one by one.

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Right. Now, let me my command line because I need to provide

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input for script, so I am going with this.

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[no audio]

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Now, let me open your script.

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'read_string_print_with_index_values',

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this is your script.

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Now, I am going to run that script, right. See that. 'Enter your string :'.

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Suppose I am entering 'python'. You can enter anything.

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See, what is happening.

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You are entering 'python'.

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[no audio]

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What I am printing?

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[no audio]

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Oh, I am printing 'usr_str', not 'each_char'.

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I want to print, then only I can get one by one character,

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right? Okay, let me rerun.

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So before going to rerun, so guys, what is the mistake

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I did means, in each and every repetition with your loop

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I am printing complete string, but I should not print complete

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string, I want to print character, whatever the character

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you are getting into this from your entire string one by

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one that character

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I want to print. That's why just now I modified your script.

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Now see I am printing each character, right. Now

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let me run your script once. I'm entering suppose 'python'.

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Yes, you are getting 'p-y-t-h-o-n' separately

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in each and every line. But while printing your character, right,

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what is our required output? 'p', some '--', arrow mark,

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then some integer number.

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So before that what I am doing is,

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[no audio]

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see I am taking 'f' strings,

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your variable value, then '--' suppose,

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in this way

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I am trying. Just see the output first.

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[no audio]

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Now I'm running this.

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I'm providing string as 'python'.

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Yes, you are getting 'p-->' symbol, but after

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that what you have to print? Here, you have to print 0, 1, 2,

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3, 4, 5, likewise based on the number of characters you have.

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See that simply what I am doing.

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[no audio]

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Where is your script?

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Yeah. See, what I am doing is I am taking, before your loop

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I am taking some index value, or simply 'ix', or simply 'index',

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let me take 'index=0'. Initially

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I'm taking index value as 0. While printing first variable

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value I will print this index as it is. See that.

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[no audio]

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Right. Now first

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let me run it so that you will get idea.

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[no audio]

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This is your script.

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What I am doing is I am printing your character and then

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index. What is the index, 0.

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[no audio]

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See guys, suppose if we enter 'python',

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I mean while running your script if you enter any string,

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[no audio]

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suppose I am entering 'python',

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so then if you observe your script, what will happen? This

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'p-y-t-h-o-n' will go and replace in this variable in your loop.

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Now, this is 'p-y-t-h-o-n'

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[no audio]

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Now your loop is going to take one by one character, and it

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is going to store in this variable and that variable we are

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printing. At the same time

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we are printing index also, but index is a constant value.

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That's why if I run our script, see the result

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what it is giving. For all characters, for all characters

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it is giving 0, but 0 is not the correct index except your 'p'.

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See, what I want to do is while printing 'p' I want to print

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initial value 0. So your loop is going to take second time second

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character from your given string.

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So before going to second, before going to get second character

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what I am doing is after your 'print' statement inside of your

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code I am increasing index value by one. 'index = index + 1'.

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[no audio]

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Now let me explain here itself. Suppose assume

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that you are entering string as 'python', then definitely your

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Python will replace in this way internally.

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Now see I am taking first 'p',

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I mean your Python and it is storing into this variable. Then

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after that whatever the lines you have those lines will repeat once.

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Right. So, while printing this index value initially it is 0, that's

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why 0 will print. Then your Python will execute next line.

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So, what you are doing? You are increasing your index value

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0 + 1 = 1. Now in your hand index value is 1. Then your Python

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will go and take next character from your given string, 'y'.

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That 'y' we are storing into this and then we are printing

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'y' and while printing index,

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what is the current index value? 0 + 1 = 1. Now, we are printing

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1. Right. Now, currently index is 1. Then after this line

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what you are doing? Again you are increasing index value

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1+1 now, that is 2. That means before going to take third

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character you are making your index value as 2, so third character

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index is always 2 only, right because 0, 1, 2. So likewise automatically

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you are increasing a variable called your required index,

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right. So now your required script you got it. Not only

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'python', you can take any variable.

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Let me run and provide simply "scripting is a good one for

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automation". Now see the result.

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Space is also one character,

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you need to remember that.

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Right. See automatically your are getting. For each and every

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character you're getting index values.

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Right. So, guys if you are able to understand these three lines and

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why I have given 'index = 0' before your loop, then

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you are good with your loops.

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[no audio]

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Suppose if I, guys, this logic you can now implement in different

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ways, but I am giving just for your, to get your idea on for

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loops I am giving in this way this example.

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Right. In case if you write 'index = 0' inside of your loop,

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then before printing your line always you are making index

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value 0. Then even though if you change here, before printing

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this line again you are making index value as 0. Always you will get 0.

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That's why whenever if you want to initialize any variable

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right, initial value, it should be there always before your

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loop. That's it.

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Now you take even simply some 'python', no problem.

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That's it. Right. Okay.

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Okay guys, thank you for watching this video.

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[no audio]