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In this tutorial we will talk about the different list method Python has several built in methods that

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can be used to modify lists.

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We will discuss some of these methods using some examples.

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This is the syntax for calling a method on an object Object dart method.

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Open Close parentheses.

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The object here would be the list

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and the list and the method is separated by the dot operator.

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And then the method say for example I want to call the append method the append method is used to add

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a single item to the end of the list.

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Say for example I want to add a number to the list.

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A list you 1

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so to the append method.

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I have passed the argument for the value forward and this value has to be added to the end of the list

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a list D1.

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So after this line of code is executed in your Jupiter book.

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This element is added to the end of the list so we will check this.

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Indeed you put book so here I have defined the list list 1 and now I'm going to apply the append method

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on this list and I'm going to parse the argument for now the append method modifies the list in place

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so it does not create a new list but it modifies the existing list that does list 1.

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So now let's display the list 1.

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So as you can see the append function has added a single item to the list.

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If we tried to add another list to an existing list.

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So what does the append method do.

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So for example this is my list a list to one.

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Let us call the append Matar.

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So I'm going to append a list to the existing list a list.

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1.

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So my new list has the element 8 some twenty three forty five.

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Now after you execute this line of code and then display the list a list is 1 as you can see here.

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D append matter come to does the argument fast to the append method as one single item and this item

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has been added to the end of the list as one single item.

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Next we will talk about the extend matter the extend method pigs and I did a bit and and each element

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of the item a bill to a list one at a time so let us understand what an ideal is.

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And I did it Bill is an object which we can either it or would do either it or word or sequence means

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to go to each of the elements of the sequence and perform some kind of operation strings tuples set

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lists are an examples of I dribbled the extend metaphor add element to a list by adding on all the elements

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of the item a bill that we passed to it.

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So once you execute the scored each of the elements of list three minus two zero and four are added

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to list to select execute this in the Jupiter notebook.

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So here I have to list this too and list three I'm going to apply the extend method on list to the extend

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metaphor takes the argument list three goes to each of the elements it lists three and add them to the

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list too.

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So let's execute this in and then display the list to as you can see here that all of these items have

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been added individually into list to to whereas consider the append method if you pass a list to the

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append method it append the entire list to the end of the existing list as a single item coming to the

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extend method.

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The extend method add each of the items individually to the list.

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Next we have just discussed about the extend method we have talked that the extend method takes and

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I editable and and each element of the item a bill to the list one at a time and thus either a bill

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can be a list set tuple or a string.

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So we have already tried to add a list to another list using the extend method.

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Now let's add a string to a list using the extend method.

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So here I have my list 3 and then I'm going to apply the extend method on the list 3 and the argument

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I have passed is a string which is an item.

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So let execute this cell and then verify list three.

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Okay so as we have discussed before the extend method goes to each of the characters in the string and

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added to the list.

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Similar to what has happened when we added to list using the extend method.

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So it retrieves each of the characters in the string.

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The first one is the character D and then or.

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And then G using the append and the extend method.

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We have seen that the lists have been modified in place.

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We can also concatenate two lists using the plus operator.

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So that the original lists are not modified the lists are concatenated and a new list is created.

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So let's see how that works.

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Let us concatenate the list list 2 and list three using the plus operator.

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So let's execute this line of code.

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So as you can see the list I listed 2 has been concatenated with list 3 and this is the result.

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Now let's display the list 2 and list 3.

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So this has not been modified.

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List 3 has not been modified as well.

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So when we can coordinate to list using the plus operator a new list is created.

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Next is the insert matter the Insert method inserts an item at a specified position within the given

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list and this is the syntax for the Insert method.

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The argument I hear is the index of the element before which to insert the Element X.

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I represent the index and X is the element which needs to be inserted into the list.

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Okay.

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This is list 3 and I'm going to insert the element mindless 7 at index 3 so let's execute this.

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Say and then display list three as you can see here the element minus seven has been inserted at index

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three.

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Next is the removed method the remove method searches for an item that is passed forward as an argument

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and removes the first matching item from the list so let's testis in the Jupiter notebook.

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So I want to remove the element forward from list three past the value forward as an argument to the

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removed method.

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Let's execute this line of code and then display list 3.

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The removed method removes the first matching item from the list.

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Next is index the index method returns the smallest list index of an element in the list and list three.

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Say for example I want to know the index of the character or the index method returns the index of that

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particular string.

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Next is the count method.

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We have seen the similar method for strings as well.

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And the account method returns the number of occurrences of an element in a list.

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Next as the pop method the pop method removes an individual item and returns to the pop method takes

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the index number as an argument.

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Say for example we want to remove the string D from the list 3 and it is it index number 3.

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So it does remove these string D from the list.

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3 that now display lists 3.

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So the pop method has removed the string D from the list 3 and here's the list 3.

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Next is the reverse method the reverse method helps to reverse the order of element in a list.

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Next is the sort method.

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The sort method can be used to start a list in the ascending order.

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Next is the copy method the copy method returns a shallow copy of a list.

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So let's understand this with an example.

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Consider this list a list of 1 and in the memory list.

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One is pointing to the elements here.

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Now if I want to create another list with the same elements I can use the assignment operator I create

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a new list a list to assign it to a list do 1 so in this case a list to do and a list do you 1.

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Pointing to the same memory location.

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So when I try to modify list 1 say using the append method I add a new element to the list C I mean

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to parse number 7.

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Now since both a listing 1 and a listing 2 are pointing to the same memory location the memory location

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now would contain all of the elements 1 2 3 4 6 and then after the append function numbered 7 has been

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added to the end of the list now both list 1 and list 2 and pointing to the updated list or the modified

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list so let's check this in the Jupiter notebook.

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So here I have the list one defined and then using the assignment operator I've copied the entire list

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one 2 list to now to verify if list to 1 and 2 are pointing to the same memory location we can use the

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identity operator is list 2 and if this returns are true that means that pointing to the same memory

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location.

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So this is true.

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Now I am going to append a new element to the list to 1 and will look past value 7 as an argument.

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So now let's display list one so the element has been added to the end of the list.

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Now let's see if you bought the list.

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That is list 1 and list two are binding to this same memory location.

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After applying the append method so you can see both the lists have been modified after applying the

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append method on one of the lists.

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If your requirement is to change or modify only one list without affecting the other list you can use

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the copy method.

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This is called the shallow copy and this is the syntax for the copy method.

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This is the original list dot com copy open and close parentheses so here I have the list.

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1 I now create another list list 3 which is a copy or list one so list one dot copy and then execute

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the cell.

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Now let us display list 3.

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OK.

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They have the same set of elements.

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List 1 and list 3.

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Now let us verify if they are pointing to the same memory location list 3 is list 1 so at the turns

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of files in this case saying they're not pointing to the same memory location.

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Now let us modify list 1 by adding a new element to list 1 so let's display list 1.

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So a new element has been added to the end of the list.

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List 1 let us display list 3.

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If it has been modified by this method no list 3 has not been modified by the append method because

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they are pointing to 2 different memory addresses.

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And this brings us to the end of this tutorial list.

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Methods.