SequentialBackoffTagger.choose_tag(tokens, index, history)[source]

Decide which tag should be used for the specified token, and return that tag. If this tagger is unable to determine a tag for the specified token, return None – do not consult the backoff tagger. This method should be overridden by subclasses of SequentialBackoffTagger.

Return type:


  • tokens (list) – The list of words that are being tagged.
  • index (int) – The index of the word whose tag should be returned.
  • history (list(str)) – A list of the tags for all words before index.