Level 4Exercise #83

Chain log batches

Flatten several log lists lazily, then return the combined list.

What you’ll practice

This Level 4 exercise focuses on chain in the Itertools curriculum. Solve the challenge prompt above using clear, idiomatic Python and the relevant language or standard-library tools.

Relevant Python reference: itertools.chain.

Sample Test Cases

Example #1

Input:combine([['a','b'],['c'],['d']])

Output:['a','b','c','d']

Reference Solution

Reveal Reference Solution

def combine(batches: list[list[str]]) -> list[str]:
    from itertools import chain
    return list(chain(*batches))

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Chain log batches

What you’ll practice

Sample Test Cases

Further Reading

Reference Solution