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[no audio]

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Friends, here we are discussing

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about 'split', 'sub', 'subn' operations

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of your 're' module.

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Let me open my Python terminal, and there I will explain. See

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anyway they are very simple operations compared to your

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'search', 'match', 'findall', 'finditer'.

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Let me open my python terminal, and let me import 're' module.

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So first operation is suppose here

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we want to discuss about 'split' operation, and if you remember

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while starting our Regular Expressions we have started

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with 'split' operation only, I mean while giving introduction.

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Anyway, here I want to show you some advanced syntax of your

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'split' operation.

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So simply write 'help(re.split)' operation, and see the

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result. We are getting some syntax, right. Now, first

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let me take 'my_srt' as,

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so, "This is about python and python is very easy

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[no audio]

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and we are having

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[no audio]

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python2 vers and python3 vers". Just assume that

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that is the string. Now suppose I want to split the given string,

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directly I'm splitting. So here is itself

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I am writing a pattern.

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Otherwise, you can also write your pattern,

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let's say, 'my_pat' as,

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[no audio]

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so I want to divide my string wherever

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'python' is there.

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Right. Now simply use 're.split' operation, your pattern,

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and your string, now see the result first.

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See wherever 'python' is there,

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there split is happening.

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But here this is capital 'P', 'Python'.

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But if you observe here this is not simply 'python',

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'python2', and 'python3'.

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Now, what I want to do is, wherever 'python2', or 'python3', and

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with 'python', then there I want to do a split. Now,

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if you observe your pattern is going to represent 'python',

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'python2' and 'python3', but of course here you are having

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capital 'P', so that you can ignore by using, by applying flags.

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Now see that, I am applying a 'flag',

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[no audio]

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case sensitivity, 'flag=', don't consider case-sensitivity,

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ignore case-sensitivity. Now see the result. Wherever 'python' is

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there, or 'python2' is there, or 'python3' is there, there

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split is happening.

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Right. So the only thing is, you have to know how to write a pattern,

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where you want to split, in which places you want to split,

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based on that places

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you need to write a pattern. Already we have gone through the

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rules to create your pattern.

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And one more thing, here if you observe here, 'maxsplit' is

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also there, right. Now,

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let me run this with 'maxsplit' as well.

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[no audio]

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Let me copy this. Directly you can write. First

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I'm applying 'maxsplit=0', and see the result.

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There is no change whether if you write 0, or I mean 'maxsplit=0',

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or if you neglect this option there is no change.

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But if I write 1, 'maxsplit', split only in one place, that

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too from left to right, the first occurred place. Now split

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in two places, that too while coming from left to right,

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this is left to right, right, left to right.

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So they're divided in two places. Now see the result. Here

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and here it is splitting. Now

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here and here

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it is not splitting.

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So that is the simple operation by using your 'split' operation.

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Right. Then we have 'sub'. Now,

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let me show you syntax for your 'sub' first. See the

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result. Pattern, I mean whatever the pattern you want, in this

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pattern whatever the word you want to replace, then your

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string, then count, then flags.

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Anyway, you know the usage of flags.

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Let me write simply,

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anyway you have your pattern, right.

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What is your pattern?

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[no audio]

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Let me write simply, your pattern.

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So 'python [23]', right. Now,

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what I am doing is, simply 'print(re.sub, in place

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of your patterns - 'python', or 'python2', or 'python3',

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I want to replace with suppose 'jython',

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in your given string.

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See the result.

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[no audio]

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Wherever 'python' is there, there we are replacing.

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But here it is not replacing because it is capital 'P'. Then

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apply 'flags' to ignore your case sensitivity.

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[no audio]

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Now, all places it is replacing. But the thing is, it is not

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going to disturb your original string. Be clear. You know

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the string properties.

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So in that case, in case if you want to store the result,

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then you can take 'my_new_str',

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I mean you can take any variable, and in that you can store it.

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Now just print your

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new string and see the result. That's it.

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Right. And if you observe here, 'count', 'count' means in how many

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places you want to replace.

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Let me directly print by applying your 'count'. 'count=0',

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see the output first. There is no change whenever if you write

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'count=0', or even if you skip that option 'count=0'.

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But if you write 'count=1', see, only the first place

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where you are occurring your pattern, there it is replacing with 'jython'

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That's it. But if you write 2, see whenever if you write 2, in 2 places

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replace my pattern with required string. This is your pattern,

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and this is your required string,

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and replace in two places only, that too while coming

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from left to right. That is the preference.

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See here and here it is replacing. That's it.

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Then what about you are 'subn' operation.

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You have one more operation, right?

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Nothing is there. It's very simple.

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Just let me run, and see the result.

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It is going to show you your result as a tuple,

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and it is giving you a resultant string, and here you are getting

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a value called 2 means, in 2 places you are replacing. Anyway,

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manually you are mentioning in 2 places replace, but you don't

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know in how many places you have your required pattern

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in a given string. Just observe that I am removing 'count=2'

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Now wherever your pattern is there, in all places you are

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going to replace with 'jython'.

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But how many places you have your required pattern in a given

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string, that it will give. Now see the result, in four places

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actually you have your required pattern in a given string, and it

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is replaced in four places with 'jython'.

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That's it. That's what it is giving.

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So this value is not depending on your 'count' value.

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But if you write 'count=2', it will replace with only

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two, that means you're going to get value 2. But if you don't

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use 'count' option in your 'sub', then in all places it

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is going to replace, but how many places it has been replaced,

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that value will be given by using 'subn' operation

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of your 're' module.

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That's it. So Guys,

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these are the simple ways to use your 'split', 'sub', and

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'subn' operations of 're' module.

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Very, very useful. Please try to do practice on this.

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Okay guys, thank you for watching this video.

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[no audio]