pycharm跑小车报错,求指导

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Traceback (most recent call last):
File "E:/hello word/Hello word.py", line 19, in
main()
File "E:/hello word/Hello word.py", line 5, in main
env = gym.make(CartPole - v0)
NameError: name 'CartPole' is not defined
求指导

没加引号
有帮助望采纳