code: def _normalize_answer(text, punc_chars, punc_repl):
      """Lower text and remove punctuation, articles and extra whitespace."""
  
      def remove_articles(s):
          return re.sub(r"\b(a|an|the)\b", " ", s)
  
      def replace_punctuation(s):
          to_replace = set(punc_chars)
          return "".join(
              punc_repl if ch in to_replace else ch for ch in s
          )
  
      def white_space_fix(s):
          return " ".join(s.split())
  
      text = text.lower()
      text = replace_punctuation(text)
      text = remove_articles(text)
      text = white_space_fix(text)
  
      return text
  
file_path: text-to-text-transfer-transformer/t5/evaluation/qa_utils.py
imports: import collections
  import re
  import string
  from absl import logging
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: _normalize_answer(text, punc_chars, punc_repl) and returns: text, re, str, str