A2C强化学习代码报错

这是我在运行A2C强化学习代码的时候遇到的问题，希望大家能提出宝贵建议，十分感谢

C:\Users\asus\AppData\Local\Programs\Python\Python37\python.exe D:/C/SUMO-changing-lane-agent-master/test.py
Traceback (most recent call last):
  File "C:\Users\asus\AppData\Local\Programs\Python\Python37\lib\site-packages\gym\envs\registration.py", line 121, in spec
    return self.env_specs[id]
KeyError: 'gym_sumo-v0'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:/C/SUMO-changing-lane-agent-master/test.py", line 6, in 
    env = gym.make('gym_sumo-v0')
  File "C:\Users\asus\AppData\Local\Programs\Python\Python37\lib\site-packages\gym\envs\registration.py", line 145, in make
    return registry.make(id, **kwargs)
  File "C:\Users\asus\AppData\Local\Programs\Python\Python37\lib\site-packages\gym\envs\registration.py", line 89, in make
    spec = self.spec(path)
  File "C:\Users\asus\AppData\Local\Programs\Python\Python37\lib\site-packages\gym\envs\registration.py", line 131, in spec
    raise error.UnregisteredEnv('No registered env with id: {}'.format(id))
gym.error.UnregisteredEnv: No registered env with id: gym_sumo-v0

KeyError: 'gym_sumo-v0'
报错是指gym没有这个环境名你查查gym的版本，以及gym环境名'gym_sumo-v0是不是对的上，一个符号都不能错的