Python Coding challenge - Day 254 | What is the output of the following Python Code?

 Explanation:

List Initialization

 (a = [1, 2, 3]):

a is a list that contains the elements [1, 2, 3].

List Comprehension

 (b = [x * 2 for x in a if x % 2 != 0]):

This is a list comprehension that constructs a new list b. List comprehensions provide a concise way to generate a new list by iterating over an existing list (in this case, a), applying an operation, and optionally filtering elements.

Let's understand it:

for x in a: This iterates through each element of the list a. So, x will take the values 1, 2, and 3 in each iteration.

if x % 2 != 0: This is a filter condition that ensures only the odd numbers are selected.

x % 2 calculates the remainder when x is divided by 2.

If the remainder is not 0 (x % 2 != 0), it means the number is odd. This condition filters out even numbers.

Therefore, only the odd numbers 1 and 3 will be included in the list.

The number 2 is even and will be excluded because 2 % 2 == 0.

x * 2: This part multiplies each odd number by 2.

When x = 1, 1 * 2 results in 2.

When x = 3, 3 * 2 results in 6.

Creating the List b:

After evaluating the list comprehension:

For x = 1 (odd), it is multiplied by 2 → 1 * 2 = 2

For x = 2 (even), it is skipped due to the filter condition.

For x = 3 (odd), it is multiplied by 2 → 3 * 2 = 6

Thus, the resulting list b is [2, 6].

print(b):

The print() function outputs the list b, which is [2, 6].

Final Output:

[2, 6]