Python Coding challenge - Day 505| What is the output of the following Python Code?

 

Code Explanation:

1. import math

Purpose: Imports the built-in Python math module, which contains mathematical functions, including sqrt (square root).

Effect: Allows you to use math.sqrt() to calculate square roots.

2. numbers = [4, 9, 16]

Purpose: Defines a list called numbers containing three integers.

Effect: This list is the input data that will be processed by the functions below.

3. def f(x):

Purpose: Defines a function named f that takes one argument x.

Effect: Prepares a function that can be called with a value to perform some operation (defined in the next line).

4. return round(x, 1)

Purpose: Inside function f, returns the value of x rounded to 1 decimal place.

Effect: This ensures the final output is a float rounded to one decimal digit.

5. def g(lst):

Purpose: Defines a function named g that takes one argument lst (expected to be a list).

Effect: Prepares a function that will process the list and return a result.

6. return sum(map(math.sqrt, lst))

Purpose:

map(math.sqrt, lst) applies the math.sqrt function to each element in the list, producing their square roots.

sum(...) adds all those square roots together.

Effect: g(lst) returns the sum of the square roots of the numbers in the list.

7. print(f(g(numbers)))

Purpose: Calls function g on the list numbers, then passes the result to function f, and prints the final output.

Step-by-step:

g(numbers) computes sqrt(4) + sqrt(9) + sqrt(16) → 2 + 3 + 4 = 9.

f(9) rounds 9 to one decimal place → 9.0.

print() outputs 9.0 to the console.

Effect: Outputs the rounded sum of square roots of the list numbers.

Final Output:

9.0