Code reviewMediumcr-g466

Subject CorrectnessLevel Mid–Senior~16 minCommon in Code quality & review interviewsIndustries Software development

Question

Review this Python validator that checks a username is exactly lowercase letters and digits, 3–16 chars.

What a strong answer looks like

Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix — specific and kind.

Learn the concepts

Talk through your review

Code to reviewpython

1import re2PATTERN = re.compile(r"[a-z0-9]{3,16}")3 4def valid_username(name: str) -> bool:5    return bool(PATTERN.match(name))

Run or narrate your approach, then ask the coach.