new_contents: import sys
  in_file = sys.stdin.readlines()
  
  
  data = map(lambda x: x.split('\t'), in_file)
  
  for line in data:
      words = ''.join(filter(lambda x: x.isalpha() or x.isspace(), line[1])).lower().split()
  
      for word in set(words):
          print(word + '\t' + line[0])
  
subject: Update mapper.py