class_docstr: Policy network, for discrete action spaces, which returns a distribution and an action given an observation.
docstr: Takes in a distribution and actions and returns log prob of actions under the distribution.
  
  Args:
      pi: torch distribution
      actions: actions taken by distribution
  
  Returns:
      log probability of the action under pi
code: def get_log_prob(self, pi: Categorical, actions: torch.Tensor):
      """Takes in a distribution and actions and returns log prob of actions under the distribution.
  
      Args:
          pi: torch distribution
          actions: actions taken by distribution
  
      Returns:
          log probability of the action under pi
  
      """
      return pi.log_prob(actions)
  
imports: import argparse
  from typing import Callable, Iterator, List, Tuple
  import gym
  import torch
  from lightning.pytorch import LightningModule, Trainer, cli_lightning_logo, seed_everything
  from torch import nn
  from torch.distributions import Categorical, Normal
  from torch.optim.optimizer import Optimizer
  from torch.utils.data import DataLoader, IterableDataset
label_desc: Use image node_id 3 for calling the ActorCategorical obj's underlying member method code with example usage: obj.get_log_prob(pi, actions) and returns: pi