Python Coding challenge - Day 160 | What is the output of the following Python Code?

 

Let's break down the code snippet step by step:

class MyClass:

    def __init__(self):

        self.__x = 10

Here, we define a class named MyClass. It has a constructor method __init__ which initializes an instance variable __x with the value 10. The __x variable is prefixed with double underscores, making it a private variable.

obj = MyClass()

We then create an instance of the MyClass class called obj. This invokes the constructor method __init__() of the MyClass class, setting the __x attribute to 10.

obj.__x = 20

Here, we try to assign a value of 20 to the __x attribute of the obj instance. However, Python is dynamically typed, so this line actually creates a new attribute __x in the obj instance, distinct from the __x attribute defined in the class. Since the attribute in the class is private, it cannot be accessed or modified directly from outside the class.

print(obj.__x)

This line tries to print the value of the __x attribute of the obj instance. However, due to the previous line, there are now two __x attributes associated with the obj instance: one created in the class and another created directly in the instance. So, obj.__x refers to the newly created attribute __x in the instance, not the one defined in the class. Therefore, it prints 20.

In summary, even though the class MyClass has a private attribute __x, the code snippet demonstrates how Python's dynamic nature allows the creation of a new instance attribute with the same name, leading to confusion about which attribute is being accessed or modified.