Python Coding Challenge - Question with Answer (ID -020126)

 

Code Explanation:

1. Importing Required Function

from functools import reduce

Explanation:

Imports the reduce() function from Python’s functools module.

reduce() is used to apply a function cumulatively to items in an iterable.

2. Creating a List of Lists

lists = [[1], [2, 3], [4]]

Explanation:

lists is a nested list (a list containing other lists).

Here:

First element → [1]

Second element → [2, 3]

Third element → [4]

3. Using reduce() to Flatten the List

result = reduce(lambda a, b: a + b, lists)

3.1 reduce()

reduce(function, iterable) repeatedly applies function to elements of iterable.

3.2 lambda a, b: a + b

This is an anonymous function.

It takes two lists (a and b) and returns their concatenation (a + b).

3.3 Step-by-step working

Step a b a + b

1 [1] [2, 3] [1, 2, 3]

2 [1, 2, 3] [4] [1, 2, 3, 4]

So the final value of result becomes:

[1, 2, 3, 4]

4. Printing the Output

print("Flattened:", result)

Explanation:

Prints the text "Flattened:" followed by the flattened list stored in result.

5. Final Output

Flattened: [1, 2, 3, 4]

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