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[no audio]

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Friends here

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we are going to see three more different operations on your

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given string.

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They are like 'count', 'index', and 'find' operations.

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See now you can easily understand 'count' operation. 'count'

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is nothing but just so you know that you're having some

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string in that given string a particular character,

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how many times it is appearing in a given string, for that

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you're using 'count' operation.

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Let me open my terminal here

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also, I mean Python Shell, Python command line.

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Let's say x = "python is easy and it is popular language"

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'x.count'. Right.

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I'm going to count how many times letter, sorry word

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"is" is there, or I am going to count only particular character.

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No problem, you can check it.

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[no audio]

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Right. Or you can check "t", or you can check letter "a".

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Right. You can check particular character or some word also.

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Let's say I am going to check.

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[no audio]

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"easy", anyway "easy"

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word is there only one time, so how many times that particular

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word or character is appearing in a given string, to count

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that you are using 'count' operation, right. Now 'x.index',

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this is next operation.

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Let's say I want to find the index of letter "p".

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See very first

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letter "p" is there, very first character "p" is there, we know

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whenever you assign string in this way, we have positive

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indexes as well as negative indexes. If we count with the

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positive, letter "p" is at 0,

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but at the same time somewhere you have "p", here and here, but

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your 'index' will give by default, whatever the 'index' operation

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you have on a given string that will look from left to right,

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and very first wherever you are getting "p" that index it will

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give. But in case if you want to look from particular position,

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I want to look from index 1. That means you are skipping index

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0. You are not searching from index 0. You're searching

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from index 1 to last. Yes, from there 25th you have. Now instead of

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25th I am looking from 26, then 27 we have one more "p" letter.

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After that do we have anything?

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Let's say I am searching from 28.

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You don't have that string in a given, after 28th index

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that's why I'm getting an error.

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Right. Not only that you can check with like "is". So let

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me check with from starting, yes somewhere in 7th index

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"is" word is starting.

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"i", index is 7. But if you try to look after some particular

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index, I want to look from 23, after 23rd index

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you don't have "is" word

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that's why it is giving an error.

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That's why you know if particular thing is there in a given string

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you can go and search with 'index' to get the index value of

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your given string.

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But anyway 'index' operation is sometimes you know, it is giving

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bad result in this way.

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[no audio]

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Right. So what I can do is 'x.find', suppose I am doing "is", or

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let's say only single character "p",

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[no audio]

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I want to look from second index, yes somewhere 25th.

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I want to look from 26th

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index, yes somewhere 27,

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I mean "p" letter is there zeroth position, 25th position, 27th

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position. I want to look from 28th.

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We are getting -1 means, now after 28th

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you don't have any "p" letter in a given string. See compared

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to 'index', right,

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you can simply forget about your 'index' operation,

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just better to remember only 'find' operation. Of course, you have

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both the things but it's better to remember 'find' operation

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to find index of your particular string, or a character.

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So how 'find' is going to work? If that particular character

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or word is there it will give the index of that, or it will give -1

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if it is not there. Suppose after 28th index, from 28th

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index up to last you don't have any "p" letter, "p" character

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in a given string that's why it is giving -1. Now if this

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result is -1, then you can say that this particular string,

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this particular character is not present from 28th to last

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index, or some so and so index to last. Let's say in entire string

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I'm looking for letter called "z", or string character called

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"z". You don't have "z" in the given string,

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because your string is like 'x' you don't have any where

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"z" in this string,

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that's why 'x.find' will give -1.

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Right. So guys this 'find' is very, very helpful in your real

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time. Instead of 'count',

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right, of course 'count' is also useful but 'find' is very, very

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useful. Let's say simply give me one example, I am trying

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to find Java version through my Python script, right?

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So you got some output, something like "java version",

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some 1.6, something like that, right. First, what I will do

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is your 'java_version.find'. First of all, I

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will check whether 'Java' is there or not in a given string.

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If it is there I will get some non-zero value,

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I mean a positive index value. Then I can say that yes, successfully

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I found Java and some Java version is there in the variable

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called 'java_version'.

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Let's say I got an output like while finding my Java version

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"Error while finding".

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[no audio]

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Now if I try to look 'Java' in the 'java_version'

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variable, you don't have. That means you are unable

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to find your Java version with the help of your logic.

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Somewhere something is wrong.

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Right. So to take some decision this value will be helpful.

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Okay. So just remember guys how to use 'find', and how it is going

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to work. While writing our scripts we will use this so that

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you will be clear how to use 'find' operation.

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Okay. So this is very, very important in your real time.

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[no audio]

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Okay guys, thank you for watching this video.

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[no audio]