class_docstr: Qa Evaluator. Now, we support metrics `'bleu'`
      
class_docstr_tok: ["Qa","Evaluator",".","Now",",","we","support","metrics","`","'bleu","'","`"]
docstr: Lower text and remove punctuation, articles and extra whitespace.
docstr_tok: ["Lower","text","and","remove","punctuation",",","articles","and","extra","whitespace","."]
code: def _normalize_answer(self, s):
      """Lower text and remove punctuation, articles and extra whitespace."""
  
      def remove_articles(text):
          return re.sub(r"\b(a|an|the)\b", " ", 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)
  
      return white_space_fix(remove_articles(remove_punc(s.lower())))
  
file_path: TextBox/textbox/evaluator/qa_evaluator.py
imports: import string
  import re
  import numpy
  from .abstract_evaluator import AbstractEvaluator
  from collections import Counter
label_desc: Use image node_id 2 for calling the QaEvaluator obj's underlying member method code with example usage: obj._normalize_answer(s) and returns: white_space_fix, re, str, str