Open In App

How to create a list of object in Python class

Last Updated : 15 Jan, 2023
Improve
Improve
Like Article
Like
Save
Share
Report

We can create a list of objects in Python by appending class instances to the list. By this, every index in the list can point to instance attributes and methods of the class and can access them. If you observe it closely, a list of objects behaves like an array of structures in C. Let’s try to understand it better with the help of examples.

 Example #1: 

Python3




# Python3 code here creating class
class geeks:
    def __init__(self, name, roll):
        self.name = name
        self.roll = roll
 
# creating list
list = []
 
# appending instances to list
list.append(geeks('Akash', 2))
list.append(geeks('Deependra', 40))
list.append(geeks('Reaper', 44))
list.append(geeks('veer', 67))
 
# Accessing object value using a for loop
for obj in list:
    print(obj.name, obj.roll, sep=' ')
 
print("")
# Accessing individual elements
print(list[0].name)
print(list[1].name)
print(list[2].name)
print(list[3].name)
 






                        










Output


Akash 2
Deependra 40
Reaper 44
veer 67

Akash
Deependra
Reaper
veer




  Example #2: 




Python3














                                    




                                    

                                    




                                    




                                    

                                    

                                    
                                




















# Python3 code here for creating class


class geeks:


    def __init__(self, x, y):


        self.x = x


        self.y = y


 


    def Sum(self):


        print(self.x + self.y)


 


 


# creating list


list = []


 


# appending instances to list


list.append(geeks(2, 3))


list.append(geeks(12, 13))


list.append(geeks(22, 33))


 


for obj in list:


    # calling method


    obj.Sum()


 


# We can also access instances method


# as list[0].Sum() , list[1].Sum() and so on.



















                        







                        










Output


5
25
55




Method #3: Using a list comprehension


This approach creates a list of objects by iterating over a range of numbers and creating a new object for each iteration. The objects are then appended to a list using a list comprehension.




Python3














                                    




                                    

                                    




                                    




                                    

                                    

                                    
                                




















# Python3 code here creating class


class geeks:


    def __init__(self, name, roll):


        self.name = name


        self.roll = roll


  


# creating list


list = []


  


# using list comprehension to append instances to list


list += [geeks(name, roll) for name, roll in [('Akash', 2), ('Deependra', 40), ('Reaper', 44), ('veer', 67)]]


  


# Accessing object value using a for loop


for obj in list:


    print(obj.name, obj.roll, sep=' ')


#This code is contributed by Edula Vinay Kumar Reddy



















                        







                        










Output


Akash 2
Deependra 40
Reaper 44
veer 67




Time complexity: O(n) where n is the number of instances being appended to the list
Auxiliary Space: O(n) as we are creating n instances of the geeks class and appending them to the list




                                    


                                                                        

                                        

                                            

                                                

                                                    
author
        

            
        

        

                                                

                                                

                                                    gyanendra371                                                

                                            

                                            

            
                                        

                                        

                                            
    

        
        
    
                                            

                                                
                                                
                                            

                                            

                                            Improve
                                                
                                            

                                        

                                    



                            

                                                            

                                    
                                        
                                        Previous Article
                                    
                                    
                                    

                                        Student management system in Python
                                    

                                

                                                            

                                    
                                        Next Article
                                        
                                    
                                    
                                    

                                        Validate an IP address using Python without using RegEx
                                    

                                

                                                        

                            

            

                

                    

                    
                
 
                
    
                            

                                

                            


                            


            

        
  
                        

                                                

                        
                                                    

                                
Similar Reads

                                

                                    
        
            

                
Object Oriented Programming in Python | Set 2 (Data Hiding and Object Printing)

                
Prerequisite: Object-Oriented Programming in Python | Set 1 (Class, Object and Members) Data hiding In Python, we use double underscore (Or __) before the attributes name and those attributes will not be directly visible outside. Python Code class MyClass: # Hidden member of MyClass __hiddenVariable = 0 # A member method that changes # __hiddenVari

            

            
            

                
                3 min read
            

        
    
        
            

                
Create Derived Class from Base Class Universally in Python

                
In object-oriented programming, the concept of inheritance allows us to create a new class, known as the derived class, based on an existing class, referred to as the base class. This facilitates code reusability and structuring. Python provides a versatile way to create derived classes from base classes universally, allowing for flexibility and sc

            

            
            

                
                3 min read
            

        
    
        
            

                
Python | Create a stopwatch using clock object in kivy using .kv file

                
Kivy is a platform-independent GUI tool in Python. As it can be run on Android, IOS, Linux and Windows, etc. It is basically used to develop the Android application, but it does not mean that it can not be used on Desktop applications. Kivy Tutorial - Learn Kivy with Examples. Clock Object: The Clock object allows you to schedule a function call in

            

            
            

                
                6 min read
            

        
    
        
            

                
Python | Create a stopwatch Using Clock Object in kivy

                
Kivy is a platform-independent GUI tool in Python. As it can be run on Android, IOS, Linux and Windows, etc. It is basically used to develop the Android application, but it does not mean that it can not be used on Desktop applications.In this, we are going to see how can we create a stopwatch using a label. In the code, we will be creating just a c

            

            
            

                
                4 min read
            

        
    
        
            

                
Create and display a one-dimensional array-like object using Pandas in Python

                
Series() is a function present in the Pandas library that creates a one-dimensional array and can hold any type of objects or data in it. In this article, let us learn the syntax, create and display one-dimensional array-like object containing an array of data using Pandas library. pandas.Series() Syntax : pandas.Series(parameters) Parameters : dat

            

            
            

                
                2 min read
            

        
    
        
            

                
Convert class object to JSON in Python

                
Conversion of the class object to JSON is done using json package in Python. json.dumps() converts Python object into a json string. Every Python object has an attribute which is denoted by __dict__ and this stores the object's attributes. Object is first converted into dictionary format using __dict__ attribute.This newly created dictionary is pas

            

            
            

                
                2 min read
            

        
    
        
            

                
Python program to create a list of tuples from given list having number and its cube in each tuple

                
Given a list of numbers of list, write a Python program to create a list of tuples having first element as the number and second element as the cube of the number. Example: Input: list = [1, 2, 3] Output: [(1, 1), (2, 8), (3, 27)] Input: list = [9, 5, 6] Output: [(9, 729), (5, 125), (6, 216)] Method #1 : Using pow() function.We can use list compreh

            

            
            

                
                5 min read
            

        
    
        
            

                
Python - Create nested list containing values as the count of list items

                
Given a list, the task is to write a Python program to create a nested list where the values are the count of list items. Examples: Input: [1, 2, 3] Output: [[1], [2, 2], [3, 3, 3]] Input: [4, 5] Output: [[1, 1, 1, 1], [2, 2, 2, 2, 2]] Method 1: Using nested list comprehension The list will contain the count of the list items for each element e in

            

            
            

                
                2 min read
            

        
    
        
            

                
Create List of Substrings from List of Strings in Python

                
In Python, when we work with lists of words or phrases, we often need to break them into smaller pieces, called substrings. A substring is a contiguous sequence of characters within a string. Creating a new list of substrings from a list of strings can be a common task in various applications. In this article, we will create a new list of substring

            

            
            

                
                3 min read
            

        
    
        
            

                
Python | Check if a given object is list or not

                
Given an object, the task is to check whether the object is list or not. Method #1: Using isinstance C/C++ Code # Python code to demonstrate # check whether the object # is a list or not # initialisation list ini_list1 = [1, 2, 3, 4, 5] ini_list2 = '12345' # code to check whether # object is a list or not if isinstance(ini_list1, list): print(&

            

            
            

                
                2 min read
            

        
                                    

                                                                    
                                                            

                        

                        

                                                            

                                    
Article Tags : 

                                    
                                                                    

                                                                                        

                                    
Practice Tags : 

                                    
                                                                    

                                                    

                                                

                                

                                    
                                                                    

                            


                        

                            

                                                                                    

                              

                            

                                                        
                        

                    

                

            

        
        


        

                




	
	
	

	
	

	
	    

	
	

	
	



                
        

    

    

        

            

            

        

    















	

    
  

  
  








    
        We use cookies to ensure you have the best browsing experience on our website. By using our site, you
        acknowledge that you have read and understood our
        Cookie Policy &
        Privacy Policy
            
    







   Lightbox