text: # Copyright 2017 Neural Networks and Deep Learning lab, MIPT
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import nltk
  
  
  class NLTKTokenizer(object):
  
      def infer(self, batch, tokenizer="wordpunct_tokenize"):
          tokenized_batch = []
  
          tokenizer_ = getattr(nltk.tokenize, tokenizer, None)
          if callable(tokenizer_):
              if type(batch) == str:
                  tokenized_batch = " ".join(tokenizer_(batch))
              else:
                  # list of str
                  for text in batch:
                      tokenized_batch.append(" ".join(tokenizer_(text)))
              return tokenized_batch
          else:
              raise AttributeError("Tokenizer %s is not defined in nltk.tokenizer" % tokenizer)
  
  
  