module ‘gym.envs.box2d’ has no attribute ‘lunarlander’

The error message “AttributeError: module ‘gym.envs.box2d’ has no attribute ‘lunarlander'” typically occurs if the LunarLander environment cannot find in the Box2D module of the OpenAI Gym library.

What is lunar lander?

LunarLander is an OpenAI Gym environment that approximates the landing of a spacecraft on the moon’s surface.

The LunarLander environment is usually used as a benchmark for testing reinforcement learning algorithms and is considered a classic problem in the field.

Also, read the other solved attributeError:

attributeerror: module gym.envs.box2d has no attribute lunarlander (occur)

Here are the multiple reasons which are the error occurs:

  • You have an outdated version of the gym library.
  • There is an issue with your installation of gym.
  • There is a bug or compatibility issue with your specific setup.

attributeerror: module ‘gym.envs.box2d’ has no attribute ‘lunarlander’ [SOLUTIONS]

Time needed: 3 minutes

Here are the steps to solve the attributeerror: module ‘gym.envs.box2d’ has no attribute ‘lunarlander’

  • Step 1: Upgrade OpenAI Gym

    The LunarLander environment was added in gym version 0.7.0, Therefore, if you have an older version of gym, you should upgrade it using the following command:

    pip install gym --upgrade

  • Step 2: Uninstall and reinstall OpenAI Gym

    You can try to uninstall and reinstall the gym library using the following commands:

    For uninstalling Gym:

    pip uninstall gym

    For reinstalling the Gym:

    pip install gym

    This will be able to help you to resolve any issues with your current installation.

  • Step 3: Check your spelling

    You ensure that you have spelled “LunarLander” correctly, with a capital “L” and “Lander”.

  • Step 4: Import directly

    You can try to import the LunarLander environment directly, you can use the following command:

    from gym.envs.box2d.lunar_lander import LunarLander

  • Step 5: Check compatibility

    Check if there are any compatibility issues between your specific setup and the gym library.

    You can try searching for similar issues on the gym GitHub repository or posting a new issue if none exist.

  • Step 6: Try a different environment

    If none of the above steps is working, you can try to use a different environment in OpenAI Gym to see if the issue is specific to the LunarLander environment or with OpenAI Gym in general.


In conclusion, the “AttributeError: module ‘gym.envs.box2d’ has no attribute ‘lunarlander’” error occurs when the “lunarlander” environment is not defined in the “box2d” module of the “gym.envs” package.

This error can be solved through updating the OpenAI Gym package, checking for the availability of the “lunarlander” environment in other modules, or installing the box2d-py package.

Though following the suggested solutions, you should be able to import the “lunarlander” environment and continue with your OpenAI Gym project.

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