def close()

in gym_hil/wrappers/viewer_wrapper.py [0:0]

• 15 lines of code
• 8 McCabe index (conditional complexity)

    def close(self) -> None:  # type: ignore[override]
        """Close both the passive viewer and the underlying gym environment.

        MuJoCo's `Renderer` gained a `close()` method only in recent versions
        (>= 2.3.0).  When running with an older MuJoCo build the renderer
        instance stored inside `env.unwrapped._viewer` does not provide this
        method which causes `AttributeError` when the environment is closed.

        To remain version-agnostic we:
          1. Manually dispose of the underlying viewer *only* if it exposes a
             `close` method.
          2. Remove the reference from the environment so that a subsequent
             call to `env.close()` will not fail.
          3. Close our own passive viewer handle.
          4. Finally forward the `close()` call to the wrapped environment so
             that any other resources are released.
        """

        # 1. Tidy up the renderer managed by the wrapped environment (if any).
        base_env = self.env.unwrapped  # type: ignore[attr-defined]
        if hasattr(base_env, "_viewer"):
            viewer = base_env._viewer
            if viewer is not None and hasattr(viewer, "close") and callable(viewer.close):
                try:  # noqa: SIM105
                    viewer.close()
                except Exception:
                    # Ignore errors coming from older MuJoCo versions or
                    # already-freed contexts.
                    pass
            # Prevent the underlying env from trying to close it again.
            base_env._viewer = None

        # 2. Close the passive viewer launched by this wrapper.
        try:  # noqa: SIM105
            self._viewer.close()
        except Exception:  # pragma: no cover
            # Defensive: avoid propagating viewer shutdown errors.
            pass

        # 3. Let the wrapped environment perform its own cleanup.
        self.env.close()