Python Coding challenge - Day 574| What is the output of the following Python Code?

 

Code Explanation:

 Function Definition

def func(a, b=None):

func is defined with:

a: required argument

b: optional argument with a default value of None

This is a safe pattern to avoid the mutable default argument trap.

Check if b is None

    if b is None:

        b = []

If the caller did not provide a list (b is None), then it creates a new list.

Append a to b

    b.append(a)

Adds the value a to the list b.

Return b

   return b

Returns the modified list.

Function Calls

Call 1:

x = func(1)

b is not passed → None

Creates a new list → b = []

Appends 1 → b = [1]

Returns [1], so x = [1]

Call 2:

x = func(2)

Again, b is not passed → None

Creates a new list again

Appends 2 → b = [2]

Returns [2], so x = [2] (overwrites previous value)

Final Output:

print(x)

Prints the most recent value of x, which is [2]

Final Output:

[2]

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