The Lazy Stream

A hard Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

hard

Seniority

L5

Problem

Given a list that may contain some inner lists (one level of nesting), return a flat list where inner lists are expanded element-by-element in place. Strings count as leaves even though iterable. Do not recurse into deeper levels.

Summary

Yield values one at a time from a potentially infinite source.

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