code: def get_perplexity(loss):
      try:
          return f"{math.pow(2, loss):.2f}"
      except OverflowError:
          return float("inf")
  
file_path: translate/pytorch_translate/evals.py
imports: import math
  import time
  from collections import defaultdict, OrderedDict
  from typing import Any, Dict, List, Optional, Tuple
  from fairseq import distributed_utils, progress_bar, utils
  from fairseq.meters import AverageMeter
  from pytorch_translate import checkpoint, generate, utils
  from pytorch_translate.dual_learning.dual_learning_task import DualLearningTask
  from pytorch_translate.tasks.pytorch_translate_multi_task import PyTorchTranslateMultiTask
label_desc: Use image node_id 5 for calling a global function with example usage: get_perplexity(loss) and returns: math, float