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Hello and welcome to this utopia on python.

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This Python lists and ordered sequins all elements.

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And the list can contain a neat assortment of objects

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undone.

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Now we have discussed about data types such as indigenous clothes strings.

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In this example here we have a variable e that refers to a memory location and this memory location

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contains the value five the variable B refers to a memory location that contains the floating value.

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Sixteen dot o the variability refers to a memory location that contains the string Python three dot

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six coming to loose a list is an ordered sequence of objects and it can contain any arbitrary objects

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such as integers loading by numbers and strings and each of the elements in a list are also called items

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the items are separated by commas and finally the items are enclosed in square brackets and this is

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known as the list.

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So this list.

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Be named as list one and a list is not merely a collection of objects.

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It is an ordered collection of objects.

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That means these are added in which we specify the elements.

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When we define a list is the special characteristic of that particular list and this order is maintained

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as long as the list is in the memory

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say for example.

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I change the order of the first two elements.

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So here I have the floating point number.

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And then an integer and then we have this string.

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So in this case these two different lists even though the elements in both the list are the same.

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So let's check this in the Jupiter note book.

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So here I have my list.

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The list is one which has three items.

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Five the integer 5 and then the floating point number sixteen dot org.

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And then a string by then three dot six.

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Now if I want to know the memory location of the memory address to which this list is pointing to.

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We use d i d function just as we used for those drawings and then integers.

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So ideal in is the one.

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So this is the memory location.

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To which the variable LSD one is pointing to.

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Now I'm going to change the positions of the first two items in the list so sixteen dot org is the first

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element and then we have the integer and then the string by then three dot six.

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So let's execute this set and then check the memory location.

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So you can see once we have changed the the position of the elements the memory location has changed

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so which means which means the order in which we specify the elements when we define a list is is the

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characteristic of that particular list

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let us now see how lists are stored in the memory.

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So in our example that we have just considered we have defined debated in E which refers to the memory

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address.

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This is the memory address and this memory address contains divide to find Nick.

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We then defined the relative in B which refers to the memory address.

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And this particular memory address contains devalue sixteen dot o which is a floating point number and

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then we have defined the word in C which refers to the memory address your and this memory address contains

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devalue Python three dots six.

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Now we have defined a list later.

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Which refers to the memory address your and this memory location contained the address of each of the

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elements in the list.

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Say for example the first element in the list is the value five and the value five is contained in this

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memory location.

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So the memory location to which the list is binding to contains the address of the first element in

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the list next.

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The value sixteen dot or is contained in this memory location here.

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So

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here we have the address of the Element sixteen Dot.

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Or next.

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The third element is the string

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but just contained in this memory location.

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So yeah we have the address the string and finally as we know this memory location contains the value

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five this one here contains the brand new sixteen dot or and this contains the string.

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So this is how lists and other data types are stored in memory.

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A list can contain any number of objects from zero to as many as your computer's memory of the number

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and list objects need not be.

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You'll need a given object again appeared in a list multiple times next list.

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Mutable once a list has been created the elements can be added deleted shifted and moved around at will.

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And by then belied a wide range of ways to modify this until now we have discussed about data types

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such as integers loads and then strings and all of these data types are immutable but less mutable and

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that add methods which can be applied on this which we will talk about and did in the later sections.

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For now we will come to.

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One method called the append method which append element to the end of the list so here we have a list

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enlistees one that has the element five sixteen dawdle and python 3.0 6.

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Now I have applied the method append on the list a list you run using D dot operator and I have POS

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D argument code.

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Now after this method is applied on the list the list will now be changed to include the element at

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the end of the list then we assign say Bill X the value 10 that means X refers to a memory address that

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contains derived Newton now.

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Later I will change the value X from 10 to 7.

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In this case what does already dead in the memory address is not changed but now x refers to a new memory

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address which contains divide 7.

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That means integers.

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Immutable.

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We cannot change any value that is on duty did in a particular memory Atlas coming to this.

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This is the list that are defined a list D1 then which contains these three elements.

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Five sixteen or and item three point six.

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Now I have applied the append method on the list listing one after this has been applied.

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The first position we have the integer 5 and then we have a floating by number and then as during and

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after that the value horde has been appended to the list.

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The data in the memory and address has been changed in case of Miss because lists are mutable.

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So let us check the memory location before and after applying the append method on the list.

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So here I have the list in one containing these three elements and Raven now call the the idea function

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on the list listing one so this is D memory location to which a list to one is adapting to now let us

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apply the append her no bias the argument for executed the same then we will display the missed it let's

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do one so devalue.

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Ford has been added to the end of the list and we will now check the memory atlas of the list a list.

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One so as you can see here the memory address has not been changed but the data in the memory location

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has been changed.

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That is the value Ford has been added to the end of the list within the same memory address next element

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in a list can be accessed individually using indexing and the individual elements in a list can be accessed

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using an index in square brackets.

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Say for example if we want to access the first element in the list the list u 1.

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This is how we treat the element.

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We place the index within square brackets.

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This is similar to what we have done for strings next.

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List indexing is zero based as it is with strings.

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So the first element are the item in the list.

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It is given an index Z or the next element has an index 1 to 3 and then so on

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Biden allows negative indexing product sequences sequences such as strings and lists.

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So LSD 1 0 minus 1 retrieves the last item in the list and trying to access an element.

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Other than this will raise an index.

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Edit the index must be an integer and we can't use a float or any other data type.

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This will result in a type error.

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So for example if we give the index as then this will throw an error because no element in the list

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with the index 10.