AttributeError: module 'gym.envs.box2d' has no attribute 'LunarLander'

[jtchen01]

System: Ubuntu 18 LTS subsystem of Windows 10

After pip installed gym, I opened python and tried to load LunarLander-v2.

I got the following message:

>>> gym.make("LunarLander-v2")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/victor/anaconda3/envs/yy/lib/python3.6/site-packages/gym/envs/registration.py", line 183, in make
    return registry.make(id, **kwargs)
  File "/home/victor/anaconda3/envs/yy/lib/python3.6/site-packages/gym/envs/registration.py", line 125, in make
    env = spec.make(**kwargs)
  File "/home/victor/anaconda3/envs/yy/lib/python3.6/site-packages/gym/envs/registration.py", line 88, in make
    cls = load(self._entry_point)
  File "/home/victor/anaconda3/envs/yy/lib/python3.6/site-packages/gym/envs/registration.py", line 18, in load
    fn = getattr(mod, attr_name)
AttributeError: module 'gym.envs.box2d' has no attribute 'LunarLander'

No immediate solution to this. I have tried to install from cloned git, or pip install it in a clean virtual machine. Neither seems to solve this issue.

[jtchen01]

Solved.

It's not gym's problem. It stems from failure to install pybox2d.

Please refer to here:
https://stackoverflow.com/questions/44198228/install-pybox2d-for-python-3-6-with-conda-4-3-21

[alik604]

pip3 install Box2D
pip3 install box2d-py
pip3 install gym[all]
pip3 install gym[Box_2D]

import gym
env = gym.make("LunarLander-v2")

you might need SWIG - I did. More info #1603 (comment)

[charlesxu90]

Problem fixed by simply running this command:

pip install Box2D

[zeeshanalipanhwar]

I am unable to install Box2D on my PyCharm env.

Building wheel for Box2D (setup.py) ... error
.
.
.
swig.exe -python -c++ -IBox2D -small -O -includeall -ignoremissing -w201 -globals b2Globals -outdir library\Box2D -keyword -w511 -D_SWIG_KWARGS -o Box2D\Box2D_wrap.
cpp Box2D\Box2D.i
  error: command 'swig.exe' failed: None
  ----------------------------------------
  ERROR: Failed building wheel for Box2D
  Running setup.py clean for Box2D
Failed to build Box2D
Installing collected packages: Box2D
    Running setup.py install for Box2D ... error
.
.
.
swig.exe -python -c++ -IBox2D -small -O -includeall -ignoremissing -w201 -globals b2Globals -outdir library\Box2D -keyword -w511 -D_SWIG_KWARGS -o Box2D\Box2D_wra
p.cpp Box2D\Box2D.i
    error: command 'swig.exe' failed: None
    ----------------------------------------

[pythonsus]

conda install swig

[jkterry1]

Please make sure to you pip install gym[box2d]