Python Coding challenge - Day 695| What is the output of the following Python Code?

 

Code Explanation:

1) import itertools

Imports the itertools module, which provides fast, memory-efficient iterators for looping and functional-style operations.

2) a = [1,2]

Creates a normal Python list a with elements [1, 2].

3) b = itertools.count(3)

itertools.count(start=3) creates an infinite iterator that starts at 3 and increases by 1 each time.

So calling next(b) repeatedly gives:

3, 4, 5, 6, ...

4) c = itertools.chain(a,b)

itertools.chain takes multiple iterables and links them together into a single sequence.

Here:

First, it yields from list a → 1, 2

Then, it continues yielding from b → 3, 4, 5, … (forever)

5) print([next(c) for _ in range(5)])

Creates a list by calling next(c) five times.

Step-by-step:

First next(c) → takes from a → 1

Second next(c) → takes from a → 2

Third next(c) → now a is exhausted, so moves to b → 3

Fourth next(c) → from b → 4

Fifth next(c) → from b → 5

Final list → [1, 2, 3, 4, 5].

Output

[1, 2, 3, 4, 5]

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