Python Coding challenge - Day 1067| What is the output of the following Python Code?

 

Code Explanation:

1. Defining Class A

class A:

    data = []

Explanation:

class A: creates a class named A.

Inside the class, a variable data is defined.

data = [] creates an empty list.

This list is a class variable, not an instance variable.

A class variable is shared by the class and all its subclasses and objects unless overridden.

So currently:

A.data → []

2. Creating Subclass B

class B(A):

    pass

Explanation:

class B(A): means B inherits from A.

pass means the class has no additional code.

Since B inherits from A, it also has access to A.data.

So:

B.data → refers to A.data

3. Creating Subclass C

class C(A):

    pass

Explanation:

class C(A): means C also inherits from A.

pass means nothing new is added.

C also inherits the class variable data from A.

So:

C.data → refers to A.data

4. Modifying the List Through B

B.data.append(10)

Explanation:

B.data refers to A.data because B inherited it.

.append(10) adds 10 to the list.

Since the list is shared, the change affects A.data and C.data as well.

Now the list becomes:

A.data → [10]

B.data → [10]

C.data → [10]

5. Printing the Values

print(A.data, C.data)

Explanation:

A.data prints the class variable of A.

C.data also refers to the same list inherited from A.

Since the list was modified earlier, both show the same value.

Final Output

[10] [10]

500 Days Python Coding Challenges with Explanation