Python Coding challenge - Day 625| What is the output of the following Python Code?

 

Code Explanation:

 1. Function Definition

def flatten(lst):

This defines a recursive generator function named flatten.

It takes one argument lst, which is expected to be a list (possibly nested).

2. For Loop: Iterating Over the List

    for item in lst:

This line iterates through each element in the list lst.

item can be an individual element (like an int or string) or another list.

3. Check for Nested List

        if isinstance(item, list):

This checks whether the current item is a list.

If it is, the function recursively calls itself to handle further flattening.

Recursive Case: Use yield from

            yield from flatten(item)

yield from is a special Python syntax that delegates iteration to another generator.

It recursively calls flatten(item) to flatten any nested sublist.

All values yielded from the recursive call are passed upward.

5. Base Case: Yield Atomic Element

        else:

            yield item

If item is not a list, it is a base value (like an integer).

The function simply yields the value, adding it to the flattened output.

6. Final Call & Output

print(list(flatten([1, [2, [3, 4], 5]])))

This calls the flatten function with a nested list.

The result is converted to a list using list(...), since flatten returns a generator.

Output:

[1, 2, 3, 4, 5]

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