What is __contains__() in Python?

Asked by Last Modified  

3 Answers

Learn Python

Follow 2
Answer

Please enter your answer

Mohit Gauniyal

Empowering Python learners with practical expertise.

__contains__() is a special method in Python that allows an object to define its own behavior when it is checked for containment in another object using the in keyword. The method should return True if the object contains the given value, and False otherwise. Here's an example that demonstrates how...
read more
__contains__() is a special method in Python that allows an object to define its own behavior when it is checked for containment in another object using the in keyword. The method should return True if the object contains the given value, and False otherwise. Here's an example that demonstrates how to use __contains__(): class MyList: def __init__(self, values): self.values = values def __contains__(self, value): return value in self.values my_list = MyList([1, 2, 3, 4, 5]) print(3 in my_list) # output: Trueprint(6 in my_list) # output: False In this example, the MyList class defines its own behavior for the in keyword by implementing the __contains__() method. The method simply checks whether the given value is in the values list and returns True or False accordingly. Note that __contains__() can be implemented for any custom object type in Python, and is often used for container types such as lists, sets, and dictionaries. read less
Comments
Dislike Bookmark

Research Engineer with 20+years experience

__contains__() is a special method in Python that allows objects to define custom behavior for the in operator. The in operator is used to test if a value is a member of a sequence or a collection. When an object defines the __contains__() method, it can be used with the in operator to determine if...
read more
__contains__() is a special method in Python that allows objects to define custom behavior for the in operator. The in operator is used to test if a value is a member of a sequence or a collection. When an object defines the __contains__() method, it can be used with the in operator to determine if a given value is contained within the object. The __contains__() method should return True if the value is present in the object, and False otherwise. Here's an example of how __contains__() can be used: class MyList: def __init__(self, data): self.data = data def __contains__(self, value): return value in self.data my_list = MyList([1, 2, 3, 4, 5]) print(3 in my_list) # Output: Trueprint(6 in my_list) # Output: False read less
Comments
Dislike Bookmark

IT Professional Trainer with 14 years of Experience

In Python, the __contains__() method is a special method that allows objects to define their own behavior when used with the in operator. It is called by the in operator to check if a given value is present in the object. The __contains__() method takes two parameters: self (representing the object...
read more
In Python, the __contains__() method is a special method that allows objects to define their own behavior when used with the in operator. It is called by the in operator to check if a given value is present in the object. The __contains__() method takes two parameters: self (representing the object itself) and item (representing the value being checked). It should return True if the item is found in the object, and False otherwise. Here's an example to illustrate the usage of __contains__() method: class MyList: def __init__(self, items): self.items = items def __contains__(self, item): return item in self.items my_list = MyList([1, 2, 3, 4, 5]) print(3 in my_list) # Output: Trueprint(6 in my_list) # Output: False In this example, we define a custom class MyList that wraps a list of items. The __contains__() method is implemented to check if an item is present in the list by using the in operator on the self.items attribute. By implementing the __contains__() method, objects of the MyList class can now be used with the in operator to check for membership of a specific value in the list. Note that if the __contains__() method is not defined for an object, Python falls back to other methods to determine the containment. For example, it checks if the object has an __iter__() method and uses it to iterate over the elements, or it checks if the object has a __getitem__() method to access the elements by index. read less
Comments
Dislike Bookmark

View 1 more Answers

Related Questions

What are the pros and cons of Python?
Python is a popular programming language that offers many benefits: ease of use, readability, and a large community of developers. However, it also has some limitations, such as slower performance compared...
Parminder
0 0
View Comments5
Where can I get Python online training?
You can get many institutes in google which are providing online training.
Taranum
Is python useful for app development?
Android doesn't support python but you can convert easily python to android app.
Prachi
I want to learn python coding. Which is the best class near mumbai which will develop my programming and clear doubts
.31622776601
Kushal
Which is the most effective institute or who is the best individual for Python Training in bangalore?
Hey, Please do specify your goals for the course. There are many good tutors teaching python. I am currently taking a class for machine learning and deep learning in python. If you are interested please do contact me and we will discuss.
Ajitesh
0 0
View Comments7

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

File Handling in Python - Basic Concept
File (Flat) Handling in Python Types of files in python: 1: Text file: Stores data in the form of characters. Customarily used to store text/string data. 2: Binary file: Stores data in the form of bytes....

Manoj S.

0 0
View Comments0
Writing Simple Programs in Python
Writing a program, especially for a beginner, is a challenging and daunting task! He/She knows the language but is not able to start. To make things simple, it is advisable to follow a process that is...

Ashish K Sharma

0 0
View Comments0
Write your first Python program in 10 minutes
1. Download python from python official site search "python download" in google 2. Install in your machine 3. verify using : "python --version" command 4. Write first program using notepad create...

Debrati Sadhu

1 0
View Comments0
What is a Decorator in Python?
🎀 What is a Decorator in Python? A decorator in Python is a powerful tool that allows you to modify or enhance the behavior of functions or methods without changing their actual code. Decorators use...

Amitava Majumder

0 0
View Comments0
10 Best Python IDEs
Python is a very popular programming language. It's open source and used today as scripting language, web development, mobile and desktop in many areas thanks to the endless modules options it has While...

Nanda Dash

0 0
View Comments0

Recommended Articles

Top 5 reasons why you should learn Python

Python is one of the most popular programming languages in the world. It is general-purpose, object oriented, high-level programming language used in a number of programming fields. Python is a great programming language to learn as it will introduce you to the world of programming. If you are from the technical background...

Read full article >

Why Should you Become an IT Consultant

Information technology consultancy or Information technology consulting is a specialized field in which one can set their focus on providing advisory services to business firms on finding ways to use innovations in information technology to further their business and meet the objectives of the business. Not only does...

Read full article >

What is Applications Engineering all about?

Applications engineering is a hot trend in the current IT market.  An applications engineer is responsible for designing and application of technology products relating to various aspects of computing. To accomplish this, he/she has to work collaboratively with the company’s manufacturing, marketing, sales, and customer...

Read full article >

Learn Microsoft Excel

Microsoft Excel is an electronic spreadsheet tool which is commonly used for financial and statistical data processing. It has been developed by Microsoft and forms a major component of the widely used Microsoft Office. From individual users to the top IT companies, Excel is used worldwide. Excel is one of the most important...

Read full article >

Find Python Training classes near you
Python Training classes in Bangalore
Python Training classes in Hyderabad
Python Training classes in Chennai
Python Training classes in Delhi
Python Training classes in Pune
Python Training classes in Mumbai
Python Training classes in Noida
Python Training classes in Kolkata
Python Training classes in Gurgaon
Python Training classes in Ghaziabad
Online Python Training

Looking for Python Training classes?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you