The Ultimate Guide to Python Programming With Python 3.10 - Singleton

The video tutorial explains the use of the __new__ and __init__ methods in Python, focusing on how to implement a Singleton pattern. It demonstrates creating a class that allows only one instance using the __new__ method. The tutorial includes testing the implementation with a card example and addresses debugging issues to ensure the Singleton pattern works correctly.

What is the primary role of the __new__ method in Python?

• To modify an existing instance of a class

• To delete an instance of a class

• To create a new instance of a class

• To initialize an object after it is created

How can the Singleton pattern be implemented using the __new__ method?

• By deleting all instances except one

• By ensuring only one instance is created and reused

• By using the __init__ method to limit instances

• By creating multiple instances and choosing one

What is the purpose of the instance class variable in the Singleton pattern?

• To hold the single instance of the class

• To initialize the class with default values

• To keep track of the number of instances created

• To store multiple instances of a class

What should happen when a second instance of a Singleton class is requested?

• A new instance should be created

• The program should terminate

• The existing instance should be returned

• An error should be raised

What issue was encountered during the testing of the Singleton implementation?

• Multiple instances were being created

• The __new__ method was not being called

• The __init__ method was not initializing correctly

• The class was not being instantiated at all

How was the initialization bug resolved in the Singleton pattern?

• By removing the __new__ method

• By modifying the __init__ method to set attributes correctly

• By creating a new class variable

• By using a different design pattern

Why is it important to correctly initialize class attributes in a Singleton?

• To maintain the Singleton behavior and avoid data loss

• To ensure the class can be instantiated multiple times

• To enable the class to be used in different modules

• To allow the class to be inherited by other classes