old_contents: # coding=utf-8
  import os
  import json
  import collections
  
  import settings
  
  import logging
  logger = logging.getLogger(__name__)
  logger.setLevel(settings.LOG_LEVEL)
  
  # preload libmecab
  import ctypes
  libdir = os.path.join(os.getcwd(), 'local', 'lib')
  libmecab = ctypes.cdll.LoadLibrary(os.path.join(libdir, 'libmecab.so'))
  
  import MeCab
  
  # prepare Tagger
  dicdir = os.path.join(os.getcwd(), 'local', 'lib', 'mecab', 'dic', 'ipadic')
  rcfile = os.path.join(os.getcwd(), 'local', 'etc', 'mecabrc')
  print "-d{} -r{}".format(dicdir, rcfile)
  default_tagger = MeCab.Tagger("-d{} -r{}".format(dicdir, rcfile))
  unk_tagger = MeCab.Tagger("-d{} -r{} --unk-feature 未知語,*,*,*,*,*,*,*,*".format(dicdir, rcfile))
  
  DEFAULT_STOPTAGS = ['BOS/EOS']
  
  def lambda_handler(event, context):
      logger.debug(json.dumps(event, ensure_ascii=False, indent=2))
  
      sentence = event.get('sentence', '').encode('utf-8')
      stoptags = event.get('stoptags', '').encode('utf-8').split(',') + DEFAULT_STOPTAGS
      unk_feature = event.get('unk_feature', False)
  
      tokens = []
      tagger = unk_tagger if unk_feature else default_tagger
      node = tagger.parseToNode(sentence)
      while node:
          feature = node.feature + ',*,*'
          part_of_speech = get_part_of_speech(feature)
          reading = get_reading(feature)
          base_form = get_base_form(feature)
          token = {
              "surface": node.surface.decode('utf-8'),
              "feature": node.feature.decode('utf-8'),
              "pos": part_of_speech.decode('utf-8'),
              "reading": reading.decode('utf-8'),
              "baseform": base_form.decode('utf-8'),
              "stat": node.stat,
          }
  
          if part_of_speech not in stoptags:
              tokens.append(token)
          node = node.next
      return {"tokens": tokens}
  
  def get_part_of_speech(feature):
      return '-'.join([v for v in feature.split(',')[:4] if v != '*'])
  
  def get_reading(feature):
      return feature.split(',')[7]
  
  def get_base_form(feature):
      return feature.split(',')[6]
  
new_contents: # coding=utf-8
  import os
  import settings
  
  import logging
  logger = logging.getLogger(__name__)
  logger.setLevel(settings.LOG_LEVEL)
  
  # preload libmecab
  import ctypes
  libdir = os.path.join(os.getcwd(), 'local', 'lib')
  libmecab = ctypes.cdll.LoadLibrary(os.path.join(libdir, 'libmecab.so'))
  
  import MeCab
  
  # prepare Tagger
  dicdir = os.path.join(os.getcwd(), 'local', 'lib', 'mecab', 'dic', 'ipadic')
  rcfile = os.path.join(os.getcwd(), 'local', 'etc', 'mecabrc')
  default_tagger = MeCab.Tagger("-d{} -r{}".format(dicdir, rcfile))
  unk_tagger = MeCab.Tagger("-d{} -r{} --unk-feature 未知語,*,*,*,*,*,*,*,*".format(dicdir, rcfile))
  
  DEFAULT_STOPTAGS = ['BOS/EOS']
  
  def lambda_handler(event, context):
      sentence = event.get('sentence', '').encode('utf-8')
      stoptags = event.get('stoptags', '').encode('utf-8').split(',') + DEFAULT_STOPTAGS
      unk_feature = event.get('unk_feature', False)
  
      tokens = []
      tagger = unk_tagger if unk_feature else default_tagger
      node = tagger.parseToNode(sentence)
      while node:
          feature = node.feature + ',*,*'
          part_of_speech = get_part_of_speech(feature)
          reading = get_reading(feature)
          base_form = get_base_form(feature)
          token = {
              "surface": node.surface.decode('utf-8'),
              "feature": node.feature.decode('utf-8'),
              "pos": part_of_speech.decode('utf-8'),
              "reading": reading.decode('utf-8'),
              "baseform": base_form.decode('utf-8'),
              "stat": node.stat,
          }
  
          if part_of_speech not in stoptags:
              tokens.append(token)
          node = node.next
      return {"tokens": tokens}
  
  def get_part_of_speech(feature):
      return '-'.join([v for v in feature.split(',')[:4] if v != '*'])
  
  def get_reading(feature):
      return feature.split(',')[7]
  
  def get_base_form(feature):
      return feature.split(',')[6]
  
subject: remove debug message and unused import