Python Coding challenge - Day 264| What is the output of the following Python Code?

 

Code Explanation:

1. nums = [5, 6, 7, 8]

This creates a list nums containing the integers [5, 6, 7, 8].

2. lambda x: x % 2 == 0

This is a lambda function, which is an anonymous or "inline" function in Python.

lambda x: x % 2 == 0 takes an input x and checks if it is even by calculating x % 2 == 0.

% is the modulus operator, which returns the remainder of a division.

An integer is even if it is divisible by 2 with no remainder (x % 2 == 0). For example:

6 % 2 == 0 (True)

7 % 2 == 0 (False)

So this lambda function returns True if the number is even, and False otherwise.

3. filter(lambda x: x % 2 == 0, nums)

filter() is a built-in Python function.

Its purpose is to filter elements in an iterable (like a list) based on a given condition or function.

The syntax is:

filter(function, iterable)

function: A function (like the lambda defined earlier) that returns True or False.

iterable: The iterable (in this case, the list nums) to filter.

Here:

function = lambda x: x % 2 == 0

iterable = nums

filter() will apply the lambda function to each element of nums. Only elements for which the lambda function returns True are included in the result.

How filter() works here:

For nums = [5, 6, 7, 8], the lambda checks:

5 % 2 == 0 → False

6 % 2 == 0 → True

7 % 2 == 0 → False

8 % 2 == 0 → True

So filter() will only keep elements 6 and 8.

4. list(filter(lambda x: x % 2 == 0, nums))

The filter() function returns an iterator, not a list. To convert it into a list, we use the list() constructor.

So:

result = list(filter(lambda x: x % 2 == 0, nums))

converts the filtered results into a list.

Here:

filter(lambda x: x % 2 == 0, nums) gives us the elements [6, 8].

list([6, 8]) converts that iterator into the list [6, 8].

5. print(result)

The final line prints the value of result.

After executing the code, result will hold [6, 8].

Final Output:

When you run the complete script:

nums = [5, 6, 7, 8]

result = list(filter(lambda x: x % 2 == 0, nums))

print(result)

The output will be:

[6, 8]