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[no audio]

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Friends here we are going to

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work with Python Regular Expressions with

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Flags. See already

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we have seen the rules to create your patterns, and these

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are the rules which we saw to create your patterns.

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[no audio]

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Right. Now we are going to work with your Regular Expressions

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with flags as well.

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So these are the available flags for your Python Regular

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Expressions. See these are the flags. You can use either shortcut

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or this flag name, both are same. Now, among all those as of

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now I am going to work and I'm going to show you with 're.i'

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and 're.m'. Later we'll work with the remaining as

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well. Now first of all, 're.i' or 're.IGNORECASE'.

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You can use either this shortcut or this full-length

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flag. Makes the regular expression case-insensitive.

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So let me open my editor. To get clarity on this

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I am writing a simple script.

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[no audio]

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'import re' module.

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Let me take some 'text=

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"this is a

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string"', and I'm writing "ThIs

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[no audio]

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is a new string", something like that.

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Then I'm writing simply all are capitals.

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[no audio]

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Now see that my requirement is, I need to find all the strings

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with "this".

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"this" string

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I need to find. Suppose if I take a pattern as in this way,

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'my_pat' as, raw string I'm taking, so that is a good practice.

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We just try to take 'r' before writing your pattern. Then

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let me print 're.findall'

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with your pattern in a given 'text'.

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What is the result you are getting? What happened?

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[no audio]

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Sorry, 'findall'.

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We're getting, 'this'. But if you don't consider case sensitivity,

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then 'this' is a 'this', and see that you have 'this' here, and

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here, and here. But I am looking for small 't-h-i-s'. But they

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are combination with small and capital and these are completely

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capital. Now,

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I don't want to look for case sensitivity, then just include

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a flag called 're.I'.

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Now see the result.

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See here I included a flag.

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[no audio]

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So you can use either 're.I' shortcut of your flag, or

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'IGNORECASE'.

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That is also same. See that. Let me rerun and see the output.

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So just use a shortcut. That's better.

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That's it.

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So this is the use of your 'IGNORECASE' sensitivity flag.

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Then we have next thing 're.M', 'MULTILINE'. See that. First

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of all let me take some multi-line text.

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[no audio]

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Let me take my 'text' as, so guys

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this is useful,

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I mean this option, 're.m' is useful whenever if you are

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going to work with files using your file object or read operation.

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Anyhow we will see that example as well. First

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let me write some string with multiple lines.

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So, "this is a string",

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and, "this is a second line", something like that.

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I am writing, and, "This is a", suppose

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[no audio]

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third line", and this. So if you have a string in this way, first

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of all this is a multi-line string. You can print and see the result.

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See you are getting output in multi lines.

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So we are giving in terms of triple quotation your string,

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that means that is a multi-line string.

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Now, what I am doing is, I am writing a pattern just to find

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'this'. 'print(re.findall)', from your pattern in the given

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multi-line text. See the result.

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Let me comment this 'print(text)'.

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Now see the result. Wherever 'this' is there you are getting that.

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Okay. Anyway, I'm looking as of now suppose small 't-h-i-s' string.

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Yes, you are getting that. Now,

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I want to print if 'this' is there at very first in a given

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string. Then I can take '^' symbol, right. See the result.

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'this', yes, in very first line you have a 'this' at very

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first. You are getting that 'this'. Then what about these two,

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eighth line and ninth line you have 'this' string, right?

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See, if you remember from our previous rules '^' - Start

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of the string and start of the line in case of multiline.

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So by default '^' will look only in the first line,

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if you have a multi-lines. But we have multi-lines and in

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multi-lines we have 'this'. If you want to look in each and

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every line, by default '^' won't look. By default '^'

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will look only in the first line, but I want to look

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in each and every line. Then you need to add a flag called

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're.m' or 're.MULTILINE'.

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Now see that. In two places at very first we have

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'this' in two lines.

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So look in all the lines, look in all multi-lines

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your Regular Expression pattern.

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That is the use of 're.m'.

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[no audio]

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Now along with your 're.m' I want to ignore case sensitivity

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as well because I need to look for this, 'This' also,

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I mean ninth line 'This' also. Capital 'T', 'h-i-s'. Then you have to

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include your case sensitivity flag as well.

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Then you have to use '|', and then you can use 're.I'.

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So if you want to work with multi-flags, you have to include

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all flags with the '|' symbol.

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[no audio]

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Right. That's it. The same way you can look for ending words as well.

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See, let me comment this.

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Let me write here, suppose this. Let me write some new thing

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'end', and here suppose I'm going to, I'm writing the 'end'. Now

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my requirement is, I want to print 'end', if 'end' is there

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at the ending in a given text or string. So pattern is, you know.

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Simply 'end', ending you're looking, '$'. Now see the result.

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[no audio]

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'end', 'end' you're getting. Why you're getting? I included

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here 're.m'. Let me remove that.

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[no audio]

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Now see that. You're not getting 'end' in the, I mean in the multi-lines

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You are going to get only in the one line.

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Sorry, ending, ending not about this.

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This is about this. See the result.

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[no audio]

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'End of the string', so in end of the string we have only 'end'

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here. But in each and every line if you want to look for your

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required string is there at the ending or not, then you need

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to include multi-line. That's it.

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At the same time if you want to include case sensitivity,

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let me write here capital 'E-n-d', or capital 'E-n-D'.

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That's it.

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[no audio]

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Okay. See guys, you can get clarity suppose if I take here and

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I am removing this multi-line.

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[no audio]

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You can keep your case sensitivity if you want.

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First let me remove multi-line. And see the result.

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You are getting only last 'end' because '$' means in

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your entire string only last line. '^' means first line

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starting, end means last line ending word. But in multi-lines

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I have 'end'. I need to find that as well. Then 're.m', and

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if you include 're.m', and if you remove 're.I' it won't work,

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because these are

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some combination with capital and small.

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Suppose if I write here small 'end', now it is going to fetch

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that because you included 're.m'. But to include this 'EnD'

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and this 'enD', you need to write case sensitivity as well.

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[no audio]

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That's it. Now see the result.

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[no audio]

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Okay.

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Okay, guys, we will see the remaining flags in later videos, okay.

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Okay guys, thank you for watching this video.

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[no audio]