# -*- coding: utf-8 -*- # Natural Language Toolkit: Interface to the Stanford Tokenizer # # Copyright (C) 2001-2017 NLTK Project # Author: Steven Xu # # URL: # For license information, see LICENSE.TXT from __future__ import unicode_literals, print_function import tempfile import os import json from subprocess import PIPE from six import text_type from nltk.internals import find_jar, config_java, java, _java_options from nltk.tokenize.api import TokenizerI _stanford_url = 'https://nlp.stanford.edu/software/tokenizer.shtml' class StanfordTokenizer(TokenizerI): r""" Interface to the Stanford Tokenizer >>> from nltk.tokenize import StanfordTokenizer >>> s = "Good muffins cost $3.88\nin New York. Please buy me\ntwo of them.\nThanks." >>> StanfordTokenizer().tokenize(s) ['Good', 'muffins', 'cost', '$', '3.88', 'in', 'New', 'York', '.', 'Please', 'buy', 'me', 'two', 'of', 'them', '.', 'Thanks', '.'] >>> s = "The colour of the wall is blue." >>> StanfordTokenizer(options={"americanize": True}).tokenize(s) ['The', 'color', 'of', 'the', 'wall', 'is', 'blue', '.'] """ _JAR = 'stanford-postagger.jar' def __init__(self, path_to_jar=None, encoding='utf8', options=None, verbose=False, java_options='-mx1000m'): self._stanford_jar = find_jar( self._JAR, path_to_jar, env_vars=('STANFORD_POSTAGGER',), searchpath=(), url=_stanford_url, verbose=verbose ) self._encoding = encoding self.java_options = java_options options = {} if options is None else options self._options_cmd = ','.join('{0}={1}'.format(key, val) for key, val in options.items()) @staticmethod def _parse_tokenized_output(s): return s.splitlines() def tokenize(self, s): """ Use stanford tokenizer's PTBTokenizer to tokenize multiple sentences. """ cmd = [ 'edu.stanford.nlp.process.PTBTokenizer', ] return self._parse_tokenized_output(self._execute(cmd, s)) def _execute(self, cmd, input_, verbose=False): encoding = self._encoding cmd.extend(['-charset', encoding]) _options_cmd = self._options_cmd if _options_cmd: cmd.extend(['-options', self._options_cmd]) default_options = ' '.join(_java_options) # Configure java. config_java(options=self.java_options, verbose=verbose) # Windows is incompatible with NamedTemporaryFile() without passing in delete=False. with tempfile.NamedTemporaryFile(mode='wb', delete=False) as input_file: # Write the actual sentences to the temporary input file if isinstance(input_, text_type) and encoding: input_ = input_.encode(encoding) input_file.write(input_) input_file.flush() cmd.append(input_file.name) # Run the tagger and get the output. stdout, stderr = java(cmd, classpath=self._stanford_jar, stdout=PIPE, stderr=PIPE) stdout = stdout.decode(encoding) os.unlink(input_file.name) # Return java configurations to their default values. config_java(options=default_options, verbose=False) return stdout def setup_module(module): from nose import SkipTest try: StanfordTokenizer() except LookupError: raise SkipTest('doctests from nltk.tokenize.stanford are skipped because the stanford postagger jar doesn\'t exist')