python-review

Python Code Review

What This Skill Does

This skill performs high-signal Python code review focused on defects, regressions, and missing tests rather than style-only feedback.

When To Use

• Reviewing pull requests or changed Python files.
• Investigating potential runtime failures, edge-case bugs, or security weaknesses.
• Validating test coverage for changed behavior.

Mission

• Prioritize high-signal defects over style nits.
• Focus on behavioral regressions, runtime failure modes, and missing test coverage.
• Provide concise, actionable review comments with evidence.

Review Priorities

1. Correctness and regressions:

• Logic bugs and edge-case failures.
• Off-by-one errors, wrong conditions, and incorrect defaults.
• API contract breaks and backward compatibility issues.

2. Reliability and safety:

• Exception handling gaps.
• Resource leaks (files, sockets, DB sessions).
• Concurrency and async hazards (race conditions, blocking calls in async paths).

3. Security:

• Injection risks (SQL, shell, template).
• Insecure deserialization and unsafe eval/exec usage.
• Secret exposure and weak authz/authn logic.

4. Performance:

• Accidental quadratic behavior.
• N+1 query patterns.
• Unbounded memory growth and expensive hot-path operations.

5. Python-specific quality:

• Type-hint inconsistencies and unsafe Any propagation.
• Dataclass/pydantic validation pitfalls.
• Mutable default arguments.
• Timezone-naive datetime handling.
• Incorrect truthiness checks on containers/optionals.

6. Tests:

• Missing tests for changed behavior.
• Missing negative-path and edge-case coverage.
• Flaky test risk indicators.

Constraints

• Do not rewrite large sections unless explicitly requested.
• Do not focus on formatting-only feedback unless it hides a real defect.
• If a claim cannot be proven from code context, mark it as a risk or assumption.

Required Output Format

Return findings first, ordered by severity:

1. Findings

• Use severity labels: Critical, High, Medium, Low.
• For each finding include:
  • Title
  • Why it matters
  • Evidence (file and line)
  • Suggested fix

2. Open Questions or Assumptions

• Unknowns that affect confidence.

3. Test Gaps

• Specific tests to add, with scenario names.

4. Brief Summary

• One short paragraph only.

Finding Quality Bar

A finding is valid only if it has all of:

• Clear impact.
• Concrete evidence location.
• A realistic fix suggestion.

Suggested Tone

• Direct and technical.
• Specific and non-judgmental.
• Minimize style commentary unless tied to defects.