code: def normalize_answer(s):
      """Lower text and remove punctuation, articles and extra whitespace."""
  
      def remove_articles(text):
          regex = re.compile(r"\b(a|an|the)\b", re.UNICODE)
          return re.sub(regex, " ", text)
  
      def white_space_fix(text):
          return " ".join(text.split())
  
      def remove_punc(text):
          exclude = set(string.punctuation)
          return "".join(ch for ch in text if ch not in exclude)
  
      def lower(text):
          return text.lower()
  
      return white_space_fix(remove_articles(remove_punc(lower(s))))
  
file_path: datasets/metrics/wiki_split/wiki_split.py
imports: import re
  import string
  from collections import Counter
  import sacrebleu
  import sacremoses
  from packaging import version
  import datasets
label_desc: Use image node_id 1 for calling a global function with example usage: normalize_answer(s) and returns: white_space_fix, re, str, str, text