Coverage for nltk.classify.mallet : 43%

# Natural Language Toolkit: Interface to Mallet Machine Learning Package 

# 

# Copyright (C) 2001-2012 NLTK Project 

# Author: Edward Loper <edloper@gradient.cis.upenn.edu> 

# URL: <http://www.nltk.org/> 

# For license information, see LICENSE.TXT 

""" 

A set of functions used to interface with the external Mallet_ machine learning 

package. Before mallet can be used, you should tell NLTK where it can find 

the mallet package, using the ``config_mallet()`` function. Typical usage: 

.. doctest:: 

    :options: +SKIP 

    >>> from nltk.classify import mallet 

    >>> mallet.config_mallet() # pass path to mallet as argument if needed 

    [Found mallet: ...] 

.. _Mallet: http://mallet.cs.umass.edu/ 

""" 

import os 

import os.path 

from nltk.internals import find_binary, java 

###################################################################### 

#{ Configuration 

###################################################################### 

_mallet_home = None 

_mallet_classpath = None 

def config_mallet(mallet_home=None): 

    """ 

    Configure NLTK's interface to the Mallet machine learning package. 

    :type mallet_home: str 

    :param mallet_home: The full path to the mallet directory. If not 

        specified, then NLTK will search the system for a mallet directory; 

        and if one is not found, it will raise a ``LookupError`` exception. 

    """ 

    global _mallet_home, _mallet_classpath 

    # We don't actually care about this binary -- we just use it to 

    # make sure we've found the right directory. 

    mallethon_bin = find_binary( 

        'mallet', mallet_home, 

        env_vars=['MALLET',  'MALLET_HOME'], 

        binary_names=['mallethon'], 

        url='http://mallet.cs.umass.edu') 

    # Record the location where mallet lives. 

    bin_dir = os.path.split(mallethon_bin)[0] 

    _mallet_home = os.path.split(bin_dir)[0] 

    # Construct a classpath for using mallet. 

    lib_dir = os.path.join(_mallet_home, 'lib') 

    if not os.path.isdir(lib_dir): 

        raise ValueError('While configuring mallet: directory %r ' 

                         'not found.' % lib_dir) 

    _mallet_classpath = os.path.pathsep.join([os.path.join(lib_dir, filename) 

                                  for filename in sorted(os.listdir(lib_dir)) 

                                  if filename.endswith('.jar')]) 

def call_mallet(cmd, classpath=None, stdin=None, stdout=None, stderr=None, 

                blocking=True): 

    """ 

    Call `nltk.internals.java` with the given command, and with the classpath 

    modified to include both ``nltk.jar`` and all the ``.jar`` files defined by 

    Mallet. 

    See `nltk.internals.java` for parameter and return value descriptions. 

    """ 

    if _mallet_classpath is None: 

        config_mallet() 

    # Set up the classpath 

    if classpath is None: 

        classpath = _mallet_classpath 

    else: 

        classpath += os.path.pathsep + _mallet_classpath 

    # Delegate to java() 

    return java(cmd, classpath, stdin, stdout, stderr, blocking)