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What is List ?

It is Mutable datatype.
It is a collection of python datatype which is enclosed by square bracket [].and each element is separated by comma (,).
For ex: x=[1,3,4,”hello”]

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Introducing CRUD Operation

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How to create list?

A list can be created by passing n number of elements within [] and each element separated by comma.

For ex; x = [1,2,3,4,”hii”,27]

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Ways to Read Data from List

list

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Indexing in python

It refers to the position of an element in a list. It can be positive indexing & negative indexing.
Positive Index start with 0 ,1,2 .. and so on and 0 denote the first element
Negative Index start with -1,-2,-3 and so on and -1 denote the last element

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Slicing in python

It used to access multiple elements from the list.
Syntax : [start : stop : step]

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Ways to update the List Elements

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Update - indexing

Update a list through indexing involve directly accessing an element at the specific position and modifying its value.
for ex: x = [1,2,34,5,6]
x[3]=13
x = [1,2,34,13,6]

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Update - slicing

Update list through slicing involves specifying a range of indices to select a portion of the list. Then we can assign new values to this slice to update the list.
Syntax for slicing: list[start:stop:step]
Where , start = The index where slice begins.
stop = The index where slice stop.
step = The step size or interval between elements in the slice

my_list = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

my_list[2:5] # Output: [2, 3, 4]

my_list[1:8:2] # Output: [1, 3, 5, 7]

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List Methods

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APPEND

Adds a single element to the end of the list.

Syntax: a.append(b)

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EXTEND

Adds all elements of an iterable (e.g., list) to the end of the list.

Syntax: a.extend(iterable)

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INSERT

Inserts an element at a specified position in the list.

Syntax: x.insert(index, element)

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How to delete list?

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Delete - indexing

Delete an item from a list by directly accessing its position and modifying the list accordingly.

x = [10, 20, 30, 40, 50]
del x[2]
print(x)
Output will be [10, 20, 40, 50]

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Delete - Slicing

"Remove an item from a list by using slicing to directly access its position and modify the list accordingly.

x = [10, 20, 30, 40, 50]
del x[2:4]
print(x)
Output will be [10, 20 50]

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How to delete list?

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Pop()

Pop: The pop operation removes and returns the last element from a list,

For example:
X = [10, 20, 30, 40, 50]
X.pop()
Print(X)
Output: X = [10, 20, 30, 40]

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remove()

Remove: The remove method deletes the first occurrence of a specified value from a list, not affecting other elements.

For example:
X = [10, 20, 30, 40, 50]
x.remove(20)
Print(x)
Output: x= [10, 30, 40]

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clear()

Clear: The clear method removes all elements from a list

For example:
x = [10, 20, 30, 40, 50]
x.clear()
print(x)

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del()

Del: The del statement removes an element at a specified index or the entire list from memory.

For example:
x = [10, 20, 30, 40, 50]
del x[2]
print(x)

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List method

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index()

index(element[, start[, end]]): Returns the index of the first occurrence of an element

For example:
x = [1, 2, 3]
x.index(2)
print(x)
Output: 1

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count()

count(element): Returns the number of occurrences of an element.

For Example:

x = [1, 2, 2, 3]

x.count(2)

Print(x)

Output: 2

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sort()

sort(key=None, reverse=False): Sorts the elements of the list in ascending order by default

For example:

x = [3, 1, 2]

x.sort()

Output: [1, 2, 3]

x.sort(reverse=True)

Output: [3, 2, 1]

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reverse()

reverse(): Reverses the elements of the list in place.

For example:

x = [1, 2, 3]

x.reverse()

Output: [3, 2, 1]

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copy()

copy(): Returns a shallow copy of the list.

For example:

x = [1, 2, 3]

y = x.copy()

Output: [1, 2, 3]