Python - Data Types - List Operations

Article

In the last session, we discussed the Python Function. Now, we will look at Python's Different Data Types and examples. The Data types are the most important topic in Python.

Let’s start,

Definition of List in Python:

A list is a mutable (changeable) data structure.
It is represented using square brackets [ ] .
Lists are used to store multiple values in a single variable.
They can hold different data types such as integers, floats, strings, and Boolean values.
Lists support adding, deleting, and modifying elements.
Lists allow duplicate values.
Commas separate multiple values in a list ( , ) .

Introduction to Lists

  
    ##check the type 
#input
list=[]
print(type(list))

#output
<class 'list'>

Create the simple List using string and numbers

  
    #Input
names=["Ram","Raja","Rani",1,2,3,4,5]
print(names)

#Output
['Ram', 'Raja', 'Rani', 1, 2, 3, 4, 5]

Create the simple List using string, numbers, float and Boolean values

  
    #input
mixed_list =[5,"Hello",3.14,True]
print(mixed_list)

#output
[5, 'Hello', 3.14, True]

Accessing or Slicing the List of Elements

  
    #input
fruits=["apple", "banana", "cherry", "kiwi", "Orange"]
print(fruits[0])
print(fruits[1])
print(fruits[4])
print(fruits[1:])
print(fruits[:1])
print(fruits[1:3])
print(fruits[-1])
Print(fruits[::-1]

#output
apple
banana
Orange
['banana', 'cherry', 'kiwi', 'Orange']
['apple']
['banana', 'cherry']
Orange
['Orange', 'kiwi', 'cherry', 'banana', 'apple']

Adding the list

  
    ## Adding Method List
#input-1 
fruits.append("pomegranate") 
print(fruits)

#Output-1
['apple', 'banana', 'cherry', 'kiwi', 'Orange', 'pomegranate']


##insert method
#input-2
fruits.insert(1,"watermelon")
print(fruits)

#output-2
['apple', 'watermelon', 'banana', 'cherry', 'kiwi', 'Orange', 'pomegranate']

##Remove method - particular element
#input-3
fruits.remove("banana")
print(fruits)

#output-3
['apple', 'watermelon', 'watermelon', 'cherry', 'kiwi', 'Orange', 'pomegranate']

##Remove Method - last element
#input-4
popped_fruits=fruits.pop()
print("The Removed Element is", popped_fruits)
print(fruits)

#output-5
The Removed Element is pomegranate
['apple', 'watermelon', 'watermelon', 'cherry', 'kiwi', 'Orange']

Modifying the List

  
    #input
fruits=["apple","banana","cherry","kiwi","Orange"]
fruits[1]="watermelon"
print(fruits)

#Output
['apple', 'watermelon', 'cherry', 'kiwi', 'Orange']

Checking the Index Method of List

  
    #input
fruits=["apple", "banana", "cherry", "kiwi", "Orange"]
index=fruits.index("cherry")
print(index)

#output
3

Sorts the list in ascending order

  
    #input
fruits = ['apple', 'watermelon', 'banana', 'cherry', 'kiwi', 'orange']
fruits.sort()
print(fruits)

#output
['apple', 'banana', 'cherry', 'kiwi', 'orange', 'watermelon']

Reverse the List

  
    #input
fruits = ['apple', 'watermelon', 'banana', 'cherry', 'kiwi', 'orange']
fruits.reverse()
print(fruits[::-1])
print(fruits)

#output
['orange', 'kiwi', 'cherry', 'banana', 'watermelon', 'apple']

Clear the List

  
    #input
fruits = ['apple', 'watermelon', 'banana', 'cherry', 'kiwi', 'orange']
fruits.clear() 
print(fruits)

#output
[ ]

Iterating the List using For loop

  
    #input
Numbers_List = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for number in Numbers_List:
    print(number)

#output
1
2
3
4
5
6
7
8
9
10

Iterating the List with index using For loop - enumerate is the special key word for identify the Index

  
    #input
Numbers_List = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for index,number in enumerate(Numbers_List):
    print(index,number)

#output
0 1
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
9 10

14 . List Comprehension Method

List comprehensions are a powerful and concise way to create lists in Python.

  
    ##Normal Method
#Input-1
list=[]
for x in range(10):
    list.append(x**2)
print(list)

#output-1
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

## List Comprehension Method
#input-2
[x**2 for x in range(10)]

#output-3
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

## List Comprehension Method
#input-2
[x for x in range(0,20,2)]

#output-3
[0, 2, 4, 6, 8, 10, 12, 14, 16, 18]

Merging Two Lists Using extend( ) keyword in Python

  
    #input
fruits1 = ["apple", "banana", "cherry", "kiwi", "Orange"]
fruits2 = ["Guva", "pomegranate"]
fruits1.extend(fruits2)
print(fruits1)

#output
['apple', 'banana', 'cherry', 'kiwi', 'Orange', 'Guva', 'pomegranate']

#Note : The extend() method adds each element of fruits2 to the end of fruits1.

Merging Two Lists Using Zip ( ) Keyword in Python

  
    #input
fruits = ["apple", "banana", "cherry", "kiwi", "Orange"]
price = [180, 90, 170, 160, 110]

fruit_prices = list(zip(fruits, price))
print(fruit_prices)

#output
[('apple', 180), ('banana', 90), ('cherry', 170), ('kiwi', 160), ('Orange', 110)]

Now, We have covered list operations with various examples and methods. In the next article, we will dive into tuple operations in Python.