The problem occured when trying 'poetry install'.

` - Installing gym (0.21.0): Failed

ChefBuildError

Backend subprocess exited when trying to invoke get_requires_for_build_wheel

error in gym setup command: 'extras_require' must be a dictionary whose values are strings or lists of strings containing valid project/version requirement specifiers.

at ~/.local/pipx/venvs/poetry/lib/python3.9/site-packages/poetry/installation/chef.py:164 in _prepare
160│
161│ error = ChefBuildError("\n\n".join(message_parts))
162│
163│ if error is not None:
→ 164│ raise error from None
165│
166│ return path
167│
168│ def _prepare_sdist(self, archive: Path, destination: Path | None = None) -> Path:

Note: This error originates from the build backend, and is likely not a problem with poetry but with gym (0.21.0) not supporting PEP 517 builds. You can verify this by running 'pip wheel --no-cache-dir --use-pep517 "gym (==0.21.0)"'.`

I searched about it and it seems to be a problem with gym(0.21.0). I have no idea how to tackle with this problem using given poetry.lock.

Is it another way to avoid this problem? Also, would it be convenient if we could upgrade to gym(>=0.22)?

Many Thanks.

Hi, thank you for writing this code I found it extremely helpful as a beginner.
I have been using this implementation in a custom environment and I had a general question.

One of the hyperparameters is n_steps, number of steps to run for each environment per update. I was wondering if there is an inherent issue if my custom environment has maximum 250 steps and loses reward for the time that passes.

Can this create a conflict and will it not learn as well? I hope my question makes sense. Please do let me know.

Thanks for the great implementation.
I found (in ppo_continuous) that the advantage is computed only once right after rollout, shouldn't it be inside the ppo epoch?

Hi sorry to bother you,

I was trying to run the the code from your wideo with Weights & Biases but I have errors when I want to run it. First of all there isn't a seed attribute for the env. To replace env.seed(seed) I have used :

env.reset(seed=seed)

Now I have an issue with:

next_obs = torch.Tensor(envs.reset()).to(device)
# Returns the error:
ValueError: expected sequence of length 4 at dim 1 (got 0)

To try and resolve it I print the tupple and converted it into an array before converting it into a Tensor :

env_reset_ar = np.asarray(envs.reset(), dtype=tuple)
next_obs = torch.Tensor(env_reset_ar).to(device) # store the initial obs 
#With env.reset() : 

#[[-0.01702683  0.02884287 -0.01968052 -0.00465021]
# [-0.00673692  0.01692973 -0.00772153  0.01331844]
# [-0.0069372   0.00867986  0.02378378  0.04562673]
# [-0.00695037  0.02889467  0.0484153  -0.01302742]]
#{} 

# But Now I have the  Error :
next_obs = torch.Tensor(env_reset_ar).to(device) # store the initial obs 
TypeError: can't convert np.ndarray of type numpy.object_. The only supported types are: float64, float32, float16, complex64, complex128, int64, int32, int16, int8, uint8, and bool.

Do you know what do I need to change to make it work ? I am still a beginner at RL so I don't know what have I done wrong.
Thank you in advance.

Kind regards,
Eliott.

I applied the code to train MountainCar-v0 but failed after 10 million timesteps. The command is as follows.

!python ppo.py --gym-id MountainCar-v0 --total-timesteps 10000000

Are these arguments correct? Or is it very hard to train MountainCar-v0 by PPO?

I want to use RNN for RL on a custom environment. My custom environment has a variable size for the observations. For example, consider the following environment:

class ModuloComputationEnv(gym.Env):
    """Environment in which an agent must learn to output mod 2,3,4 of the sum of
       seen observations.

    Observations are squences of integer numbers ,
    e.g. (1,3,4,5)

    The action space is just 3 values first for the sum of inputs till now %2, second %3 
    and third %4.

    Rewards are r=-abs(self.ac1-action[0]) - abs(self.ac2-action[1]) - abs(self.ac3-action[2]), 
    for all steps.
    """

    def __init__(self, config):
        
        #the input sequence can have any number from 0,99
        self.observation_space = Sequence(Discrete(100), seed=2)

        #the action is a vector of 3, [%2, %3, %4], of the sum of the input sequence
        self.action_space = MultiDiscrete([2,3,4])

        self.cur_obs = None
        
        #this variable maintains the episode_length
        self.episode_len = 0

        #this variable maintains %2
        self.ac1 = 0
        
        #this variable maintains %3
        self.ac2 = 0

        #this variable maintains %4
        self.ac3 = 0

    def reset(self, *, seed=None, options=None):
        """Resets the episode and returns the initial observation of the new one.
        """

        # Reset the episode len.
        self.episode_len = 0
        
        # Sample a random sequence from our observation space.
        self.cur_obs = self.observation_space.sample()

        #take the sum of the initial observation
        sum_obs = sum(self.cur_obs)

        #consider the %2, %3, and %4 of the initial observation
        self.ac1 = sum_obs%2
        self.ac2 = sum_obs%3
        self.ac3 = sum_obs%4

        # Return initial observation.
        return self.cur_obs, {}

    def step(self, action):
        """Takes a single step in the episode given `action`

        Returns:
            New observation, reward, done-flag, info-dict (empty).
        """
        # Set `truncated` flag after 10 steps.
        self.episode_len += 1
        truncated = False
        terminated = self.episode_len >= 10

        #the reward is the negative of further away from computing the individual values
        reward = abs(self.ac1-action[0]) + abs(self.ac2-action[1]) + abs(self.ac3-action[2])
        reward = -reward


        # Set a new observation (random sample).
        self.cur_obs = self.observation_space.sample()

        #recompute the %2, %3 and %4 values
        self.ac1 = (self.cur_obs+self.ac1)%2
        self.ac2 = (self.cur_obs+self.ac2)%3
        self.ac3 = (self.cur_obs+self.ac3)%4
        
        return self.cur_obs, reward, terminated, truncated, {}