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Python wrapper for Stanford CoreNLP tools

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README.md

Python interface to Stanford Core NLP tools v1.3.3

This is a Python wrapper for Stanford University's NLP group's Java-based CoreNLP tools. It can either be imported as a module or run as a JSON-RPC server. Because it uses many large trained models (requiring 3GB RAM on 64-bit machines and usually a few minutes loading time), most applications will probably want to run it as a server.

  • Python interface to Stanford CoreNLP tools: tagging, phrase-structure parsing, dependency parsing, named entity resolution, and coreference resolution.
  • Runs an JSON-RPC server that wraps the Java server and outputs JSON.
  • Outputs parse trees which can be used by nltk.

It requires pexpect and (optionally) unidecode to handle non-ASCII text. This script includes and uses code from jsonrpc and python-progressbar.

It runs the Stanford CoreNLP jar in a separate process, communicates with the java process using its command-line interface, and makes assumptions about the output of the parser in order to parse it into a Python dict object and transfer it using JSON. The parser will break if the output changes significantly, but it has been tested on Core NLP tools version 1.3.3 released 2012-07-09.

Download and Usage

To use this program you must download and unpack the tgz file containing Stanford's CoreNLP package. By default, corenlp.py looks for the Stanford Core NLP folder as a subdirectory of where the script is being run.

In other words:

sudo pip install pexpect unidecode   # unidecode is optional
git clone git://github.com/dasmith/stanford-corenlp-python.git
  cd stanford-corenlp-python
wget http://nlp.stanford.edu/software/stanford-corenlp-2012-07-09.tgz
tar xvfz stanford-corenlp-2012-07-09.tgz

Then, to launch a server:

python corenlp.py

Optionally, you can specify a host or port:

python corenlp.py -H 0.0.0.0 -p 3456

That will run a public JSON-RPC server on port 3456.

Assuming you are running on port 8080, the code in client.py shows an example parse:

import jsonrpc
from simplejson import loads
server = jsonrpc.ServerProxy(jsonrpc.JsonRpc20(),
        jsonrpc.TransportTcpIp(addr=("127.0.0.1", 8080)))

result = loads(server.parse("Hello world.  It is so beautiful"))
print "Result", result

That returns a dictionary containing the keys sentences and (when applicable) corefs. The key sentences contains a list of dictionaries for each sentence, which contain parsetree, text, tuples containing the dependencies, and words, containing information about parts of speech, NER, etc:

{u'sentences': [{u'parsetree': u'(ROOT (S (VP (NP (INTJ (UH Hello)) (NP (NN world)))) (. !)))',
                 u'text': u'Hello world!',
                 u'tuples': [[u'dep', u'world', u'Hello'],
                             [u'root', u'ROOT', u'world']],
                 u'words': [[u'Hello',
                             {u'CharacterOffsetBegin': u'0',
                              u'CharacterOffsetEnd': u'5',
                              u'Lemma': u'hello',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'UH'}],
                            [u'world',
                             {u'CharacterOffsetBegin': u'6',
                              u'CharacterOffsetEnd': u'11',
                              u'Lemma': u'world',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'NN'}],
                            [u'!',
                             {u'CharacterOffsetBegin': u'11',
                              u'CharacterOffsetEnd': u'12',
                              u'Lemma': u'!',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'.'}]]},
                {u'parsetree': u'(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADJP (RB so) (JJ beautiful))) (. .)))',
                 u'text': u'It is so beautiful.',
                 u'tuples': [[u'nsubj', u'beautiful', u'It'],
                             [u'cop', u'beautiful', u'is'],
                             [u'advmod', u'beautiful', u'so'],
                             [u'root', u'ROOT', u'beautiful']],
                 u'words': [[u'It',
                             {u'CharacterOffsetBegin': u'14',
                              u'CharacterOffsetEnd': u'16',
                              u'Lemma': u'it',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'PRP'}],
                            [u'is',
                             {u'CharacterOffsetBegin': u'17',
                              u'CharacterOffsetEnd': u'19',
                              u'Lemma': u'be',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'VBZ'}],
                            [u'so',
                             {u'CharacterOffsetBegin': u'20',
                              u'CharacterOffsetEnd': u'22',
                              u'Lemma': u'so',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'RB'}],
                            [u'beautiful',
                             {u'CharacterOffsetBegin': u'23',
                              u'CharacterOffsetEnd': u'32',
                              u'Lemma': u'beautiful',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'JJ'}],
                            [u'.',
                             {u'CharacterOffsetBegin': u'32',
                              u'CharacterOffsetEnd': u'33',
                              u'Lemma': u'.',
                              u'NamedEntityTag': u'O',
                              u'PartOfSpeech': u'.'}]]}],
u'coref': [[[[u'It', 1, 0, 0, 1], [u'Hello world', 0, 1, 0, 2]]]]}

To use it in a regular script or to edit/debug it (because errors via RPC are opaque), load the module instead:

from corenlp import *
corenlp = StanfordCoreNLP()  # wait a few minutes...
corenlp.parse("Parse it")

Questions

Stanford CoreNLP tools require a large amount of free memory. Java 5+ uses about 50% more RAM on 64-bit machines than 32-bit machines. 32-bit machine users can lower the memory requirements by changing -Xmx3g to -Xmx2g or even less. If pexpect timesout while loading models, check to make sure you have enough memory and can run the server alone without your kernel killing the java process:

java -cp stanford-corenlp-2012-07-09.jar:stanford-corenlp-2012-07-06-models.jar:xom.jar:joda-time.jar -Xmx3g edu.stanford.nlp.pipeline.StanfordCoreNLP -props default.properties

You can reach me, Dustin Smith, by sending a message on GitHub or through email (contact information is available on my webpage).

Contributors

This is free and open source software and has benefited from the contribution and feedback of others. Like Stanford's CoreNLP tools, it is covered under the GNU General Public License v2 +, which in short means that modifications to this program must maintain the same free and open source distribution policy.

This project has benefited from the contributions of:

  • @jcc Justin Cheng
  • Abhaya Agarwal

Related Projects

These two projects are python wrappers for the Stanford Parser, which includes the Stanford Parser, although the Stanford Parser is another project.

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