How to Propagate X-Request-ID in Python

import uuid


def generate_request_id() -> str:
    """Generate a unique request ID similar to X-Request-ID header."""
    return str(uuid.uuid4())


def propagate_request_id(request_id: str | None) -> str:
    """Return the request ID for propagation, generating one if missing."""
    if request_id:
        return request_id
    return generate_request_id()


if __name__ == "__main__":
    # Simulate an incoming request without an X-Request-ID
    incoming = None
    propagated = propagate_request_id(incoming)
    print(f"Incoming X-Request-ID: {incoming}")
    print(f"Propagated X-Request-ID: {propagated}")

    # Simulate an incoming request that already has an X-Request-ID
    incoming_with_id = "7f9c1b2a-3d4e-4f5a-9b8c-1d2e3f4a5b6c"
    propagated_with_id = propagate_request_id(incoming_with_id)
    print(f"\nIncoming X-Request-ID: {incoming_with_id}")
    print(f"Propagated X-Request-ID: {propagated_with_id}")