mellea.stdlib.requirements.python_reqs

Requirements for Python code generation validation.

Requirements for Python code generation validation.

Classes

CLASS PythonExecutionReq

Verifies that Python code runs without raising exceptions.

Optionally validates that captured stdout does not exceed a size limit, eliminating the double-execution cost of separate OutputSizeLimit checks.

Extracts the highest-scoring Python code block from the model’s last output and validates or executes it according to the configured execution tier.

Use execution_tier to select behavior by intent:

• "static" (default) — parse and import-check only, no execution.
• "local_unsafe" — subprocess execution, no policy restrictions.
• "local" — subprocess execution with a declared capability policy.
• "docker_unsafe" — Docker-isolated execution, no policy restrictions.
• "docker" — Docker-isolated execution with a declared capability policy.

Args:

• execution_tier: One of "static", "local_unsafe", "local", "docker_unsafe", or "docker". Defaults to "static".
• policy: Override the tier’s default policy. Ignored for "static" and unsafe tiers unless explicitly provided.
• allowed_imports: Allowlist of importable top-level modules. None allows any import.
• max_output_chars: Maximum allowed stdout size in characters. None = no size check (default). When set, adds output size validation in the same execution pass, avoiding the double-execution cost of using OutputSizeLimit. Only enforced for tiers that execute code (local_unsafe, local, docker_unsafe, docker); static tier skips output check.
• timeout: Deprecated. Pass policy=CapabilityPolicy(timeout=N) instead. When provided, overrides the policy timeout.
• allow_unsafe_execution: Deprecated. Use execution_tier="local_unsafe" instead.
• use_sandbox: Deprecated. Use execution_tier="docker" instead.

Attributes:

• validation_fn: The validation function attached to this requirement; always non-None.