用pytorch写一下深度强化学习的相关代码

好的，深度强化学习的代码相对比较复杂，我可以提供一个简单的代码框架，供您参考。

首先，需要导入相关的库：

import torch
import torch.nn as nn
import torch.optim as optim
import gym
from collections import deque
import random

接下来，定义一个神经网络类，用于作为深度强化学习的模型：

class DQN(nn.Module):
    def __init__(self, state_dim, action_dim):
        super(DQN, self).__init__()
        self.fc1 = nn.Linear(state_dim, 64)
        self.fc2 = nn.Linear(64, 64)
        self.fc3 = nn.Linear(64, action_dim)

    def forward(self, x):
        x = torch.relu(self.fc1(x))
        x = torch.relu(self.fc2(x))
        x = self.fc3(x)
        return x

接下来，定义一个深度强化学习的类：

class DQNAgent:
    def __init__(self, state_dim, action_dim, replay_buffer_size=10000, batch_size=32, gamma=0.99, epsilon=1.0, epsilon_min=0.01, epsilon_decay=0.995, learning_rate=0.001):
        self.state_dim = state_dim
        self.action_dim = action_dim
        self.memory = deque(maxlen=replay_buffer_size)
        self.batch_size = batch_size
        self.gamma = gamma
        self.epsilon = epsilon
        self.epsilon_min = epsilon_min
        self.epsilon_decay = epsilon_decay
        self.learning_rate = learning_rate
        self.model = DQN(state_dim, action_dim)
        self.optimizer = optim.Adam(self.model.parameters(), lr=learning_rate)

    def act(self, state):
        if random.uniform(0, 1) < self.epsilon:
            return random.randint(0, self.action_dim - 1)
        else:
            state = torch.tensor(state, dtype=torch.float32).unsqueeze(0)
            q_values = self.model(state)
            return torch.argmax(q_values, dim=1).item()

    def remember(self, state, action, reward, next_state, done):
        self.memory.append((state, action, reward, next_state, done))

    def replay(self):
        if len(self.memory) < self.batch_size:
            return
        batch = random.sample(self.memory, self.batch_size)
        states, actions, rewards, next_states, dones = zip(*batch)
        states = torch.tensor(states, dtype=torch.float32)
        actions = torch.tensor(actions, dtype=torch.int64).unsqueeze(1)
        rewards = torch.tensor(rewards, dtype=torch.float32).unsqueeze(1)
        next_states = torch.tensor(next_states, dtype=torch.float32)
        dones = torch.tensor(dones, dtype=torch.float32).unsqueeze(1)
        
        q_values = self.model(states).gather(1, actions)
        next_q_values = self.model(next_states).max(dim=1, keepdim=True)[0]
        target_q_values = rewards + (1 - dones) * self.gamma * next_q_values
        loss = nn.MSELoss()(q_values, target_q_values)
        
        self.optimizer.zero_grad()
        loss.backward()
        self.optimizer.step()

        if self.epsilon > self.epsilon_min:
            self.epsilon *= self.epsilon_decay

最后，我们可以用这个深度强化学习的类来训练模型：

env = gym.make('CartPole-v1')
agent = DQNAgent(env.observation_space.shape[0], env.action_space.n)

for episode in range(1000):
    state = env.reset()
    done = False
    total_reward = 0
    while not done:
        action = agent.act(state)
        next_state, reward, done, _ = env.step(action)
        agent.remember(state, action, reward, next_state, done)
        state = next_state
        total_reward += reward
    print('Episode: {}, Total Reward: {}'.format(episode, total_reward))
    agent.replay()

这段代码用于训练 CartPole 游戏，可以根据需要修改游戏名称、观测空间和动作空间等参数。