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Coming back to our actual program, let us go to our Demo Morton now here we have defined the main function

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that we set, the values of the variables.

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My message, SDR and my guests, when they are called.

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Now, the rest of the program will also have a function mean that is called at the start of each program.

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The reason we are having a main function is explained at the end of when we conclude a particular session.

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And over here we have the variables, my messages, a certain mixture which stores the plain text message

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to encrypt and the key which is used to do the encryption.

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Now, over here, we also have a variable ciphertext, ETR, which is an encrypted message by calling

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the function that takes the argument.

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So over here, this will be stored as an encrypted message that will come from the message or from the

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function, encrypted messages to the code that does the actual encrypting is in the definition encrypted

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message, Asgeir function, which is defined the later.

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Now this function takes two arguments, an integer value for the key and a string value for the message

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to encrypt.

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So in this case, we have passed my messages and my estimate now when passing a multiple argument to

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the function called separate the argument with the bombing that we have passed over here.

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So the return value of the encrypt messages is a string value of an encrypted ciphertext, and this

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is stored in the variable ciphertext SDR.

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Now, the ciphertext e-mail still messages printed on the screen and copied to the clipboard.

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When we say here, print and not copy.

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Now the program prints up by character at the end of the message so that the user can see any empty

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space characters at the end of the ciphertext.

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After execution is done, the program execution's returns to the line after the line that is called

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or call the particular main function.

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So the key and the message variable between the parentheses or the parameters.

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When we define the encrypt messages, it takes basically two arguments in this case, like the value

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in Michael Asgeir and the messages to these values are assigned to the parameter key and the message

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when the execution moves to the top of the function.

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Now, you might wonder of how you need to have the key and the message parameter since you only have

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a variables as my keister and my messages during the main function.

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But we need different variables because the mike is different in my messages during the main function

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at of local scope and cannot be used outside the particular main function.

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Now when we come to the next, that is the list data type.

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So over here, if you see we have created ciphertext SDR in the particular function by giving square

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bracket single open, closed, multiplied by Kirsti.

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Now, before we can move on, you need to understand how the list works and what do you get out of the

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particular list.

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List value can contain other values also similar to how string begin and end with a quote.

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A list value begins with an open bracket and ends with a closed bracket and the value stored inside

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the list are between the brackets.

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So if more than one value is in the list, the values are separated by commas.

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For example, if we want to see a list in action, we will enter something into the interactive shell

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over here like we would give sea animals.

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SDR is equal to we give sea dog got a horse elephant.

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We have defined this.

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Then here you just say in the next line, animals SDR, we get all the values.

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Prenter So here the animals Asgeir that we have available store a list of values.

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And in this list, values are basically four strings that we have created.

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So over here, the four string values are stored individually there.

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So the individual value inside the list is also called as an item or an element.

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No list are ideal to use.

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Then you have to store multiple values in one variable for many of the operations you can do with strings.

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Also work with list, for example, indexing or slicing Volks on list values the same way that works

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on this string values instead of individual characters in a particular string, the index refers to

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an item in a particular list.

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For example, if we say here, see animals SDR Index zero, we get the default index or if we see animals

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SDR Index two, we get there.

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The third item apart in the particular list, or if we see animals SDR in brackets one column three,

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we get that value for.

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One, bill, three.

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So keep in mind that the forced index is zero and not one so similar to how you use liasing with a string

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gives you a new string, and that is a part of the original strength.

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Using Fleisig with list gives you a list that is a part of the original list.

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And also remember that if a slice has a second indexed, life only goes up to but doesn't include the

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item at the second index.

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Now you can also use a for loop for iterating over values in the list, just like we can.

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I trade over characters in a particular string.

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For example, if you say for S1 in again we use on our list.

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So we give some again the same values comma clause it open this column and here we give Ziprin for the

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know we are cooking, plus the value of S1.

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And so we get for dinner, we are cooking dog got hot, so everywhere this value of one is automatically

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replaced and that is what is printed.

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So each time your loop is iterating, the S1 variable is assigned a new value from the list, starting

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with the list zero index until the end of the particular list.

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You can also reassign the items in the list.

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Now, for example, say here, as we have defined animala steerable, let's define that again.

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Animals Asscher is equal to give.

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There again the same items.

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We have defined this now we say here animals SDR at the index.

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Do we want to make there something like nine nine nine nine and now we see animals osteotomy are to

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be printed.

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So now we have replaced that value to modify an element or third element of the particular list.

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We have used the index to get the total value with using animal instead of the index two and then use

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an assignment statement to change its value from the original one to a new value.

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So when we check the content of the list again now the earlier animal resource horse is no longer existing

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in a particular given list.

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Now, similar to this, how can you have list of let's list values can even contain other list values.

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For example, let's create list one here is equal to recreate, say, dog cat one and it give a comma.

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Next we have the number one three five, for example, and then close it.

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Now if we see list one, index zero, we get the first list.

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If we say list one zero zero, we get the full stroke, first column value.

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Similarly, if we say list one says zero one, we get the next value.

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If we say list one second row, first column, we get the value one.

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Similarly, list one, one one.

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Or if you want to it, say list one, one, two, because that is having one more value inside it.

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So here the value of the list, one evaluates to the list that is dog at first, which has its own indexes.

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The double index brackets over here, that is, we have use list one zero zero indicate that we are

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taking the first item from the first list.

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If we only say list zero, it evaluates to the whole of the first list.

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And if we see list one in the index zero zero, it goes to the first value in the first list.

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That is dog.

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Similarly, you can also use the length and the operator with the list.

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Now you have also used the length method, which is there to indicate a number of characters in a particular

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strip.

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The length function also walks on list values and returns an integer of the number of list or items

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in a particular list.

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For example, if we see we animal length of C animals.

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SDR, may the lenders for similarly, you have also used the in and not in operators to indicate whether

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a string exists inside another string values.

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The end operator also looks for checking whether a value exist in a list and they not in operator checks

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whether a value does not exist in the particular list.

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Now, for example, if we try to see value, say, log in any Nestea, we get the value to.

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If we say dog sorry, in string dog one in animal Asscher, that is coming to Foote's.

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Similarly, if we see a dog one say not in any Melissia comes through.

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Right.

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This is all we can use the particular values there.

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So now coming to the list, concatenation and replication with plus and the multiplication operators'.

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Now you know that the plus and the multiplication operators can concatenate and replicate the strings.

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Same operators can also concatenate and replicate your list now, for example, of something into the

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interactive schill c v right down here, C Python.

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And plus again here we enter C hacking together python hacking.

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OK, similarly, if we see Python multiplied by five, we get five times Python Prenter.

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Now that's enough about the similarities that we have seen between strings and this almost whatever

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we can work on string, we can also work it on the list.

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So just remember the most operations you can do with string values.

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Also work with your list of values.