Python Coding challenge - Day 571| What is the output of the following Python Code?

 

Code Explanation:

1. Function Definition

def test(x, y=5, z=None):

This defines a function named test with three parameters:

x: required argument.

y: optional argument with a default value of 5.

z: optional argument with a default value of None.

z is initialized as None by default to avoid using mutable default arguments (like lists), which can cause bugs.

2. Check if z is None

    if z is None:

        z = []

This checks if the caller has provided a value for z.

f not (z is None), a new empty list [] is created.

This ensures each function call gets a fresh list instead of reusing a shared one.

3. Append the Sum of x and y to z

    z.append(x + y)

The function adds x + y and appends the result to the list z.

4. Return the List

    return z

The modified list z is returned.

5. Function Call and Print

print(test(1), test(2))

Let's break this down further:

First Call: test(1)

x = 1, y = 5 (default), z = None

z becomes []

1 + 5 = 6, so z = [6]

Returns [6]

Second Call: test(2)

x = 2, y = 5 (default), z = None

A new empty list z = [] is created

2 + 5 = 7, so z = [7]

Returns [7]

6. Final Output

[6] [7]

The output of print(test(1), test(2)) is:

[6] [7]

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