Python Coding challenge - Day 275| What is the output of the following Python Code?

Step-by-Step Explanation:

Line 1: Function Definition

def func(a, b=[]):

This defines a function func() that takes two arguments:

a: A required parameter.

b: An optional parameter with a default value of an empty list [].

Key Point: The default argument b=[] is evaluated only once at the time of function definition, and the same list object is reused across multiple calls to the function if not explicitly provided.

Line 2: Modify List

    b.append(a) 

The method append(a) adds the value of a to the list b.

Important Note: If the list b is shared across multiple calls due to the default argument, modifications will persist between calls.

Line 3: Return the List

    return b

The function returns the list b after appending the value of a to it.

Line 4: Call the function with 1

print(func(1))

When you call func(1), the default b=[] is used (an empty list at first).

The value 1 is appended to b.

The function returns [1].

[1]

Line 5: Call the function with 2

print(func(2))

Now, the function is called with func(2). The default list b is the same list object as the one used in the previous call.

The value 2 is appended to this same list.

The returned list now becomes [1, 2].

Output:

[1, 2]