365 lines
12 KiB
Python
365 lines
12 KiB
Python
# -*- coding: utf-8 -*-
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# Natural Language Toolkit: Compatibility
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#
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# Copyright (C) 2001-2018 NLTK Project
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#
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# URL: <http://nltk.org/>
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# For license information, see LICENSE.TXT
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from __future__ import absolute_import, print_function
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import os
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import sys
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from functools import update_wrapper, wraps
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import fractions
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import unicodedata
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from six import string_types, text_type
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# Python 2/3 compatibility layer. Based on six.
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PY3 = sys.version_info[0] == 3
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if PY3:
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def get_im_class(meth):
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return meth.__self__.__class__
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import io
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StringIO = io.StringIO
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BytesIO = io.BytesIO
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from datetime import timezone
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UTC = timezone.utc
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from tempfile import TemporaryDirectory
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else:
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def get_im_class(meth):
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return meth.im_class
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try:
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from cStringIO import StringIO
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except ImportError:
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from StringIO import StringIO
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BytesIO = StringIO
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from datetime import tzinfo, timedelta
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ZERO = timedelta(0)
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HOUR = timedelta(hours=1)
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# A UTC class for python 2.7
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class UTC(tzinfo):
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"""UTC"""
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def utcoffset(self, dt):
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return ZERO
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def tzname(self, dt):
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return "UTC"
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def dst(self, dt):
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return ZERO
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UTC = UTC()
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import csv
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import codecs
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import cStringIO
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class UnicodeWriter:
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"""
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A CSV writer which will write rows to CSV file "f",
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which is encoded in the given encoding.
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see https://docs.python.org/2/library/csv.html
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"""
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def __init__(self, f, dialect=csv.excel, encoding="utf-8",
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errors='replace', **kwds):
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# Redirect output to a queue
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self.queue = cStringIO.StringIO()
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self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
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self.stream = f
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encoder_cls = codecs.getincrementalencoder(encoding)
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self.encoder = encoder_cls(errors=errors)
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def encode(self, data):
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if isinstance(data, string_types):
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return data.encode("utf-8")
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else:
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return data
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def writerow(self, row):
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self.writer.writerow([self.encode(s) for s in row])
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# Fetch UTF-8 output from the queue ...
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data = self.queue.getvalue()
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data = data.decode("utf-8")
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# ... and reencode it into the target encoding
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data = self.encoder.encode(data, 'replace')
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# write to the target stream
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self.stream.write(data)
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# empty queue
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self.queue.truncate(0)
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import warnings as _warnings
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import os as _os
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from tempfile import mkdtemp
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class TemporaryDirectory(object):
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"""Create and return a temporary directory. This has the same
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behavior as mkdtemp but can be used as a context manager. For
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example:
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with TemporaryDirectory() as tmpdir:
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...
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Upon exiting the context, the directory and everything contained
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in it are removed.
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http://stackoverflow.com/questions/19296146/tempfile-temporarydirectory-context-manager-in-python-2-7
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"""
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def __init__(self, suffix="", prefix="tmp", dir=None):
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self._closed = False
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self.name = None # Handle mkdtemp raising an exception
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self.name = mkdtemp(suffix, prefix, dir)
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def __repr__(self):
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return "<{} {!r}>".format(self.__class__.__name__, self.name)
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def __enter__(self):
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return self.name
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def cleanup(self, _warn=False):
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if self.name and not self._closed:
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try:
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self._rmtree(self.name)
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except (TypeError, AttributeError) as ex:
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# Issue #10188: Emit a warning on stderr
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# if the directory could not be cleaned
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# up due to missing globals
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if "None" not in str(ex):
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raise
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print("ERROR: {!r} while cleaning up {!r}".format(ex,
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self),
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file=sys.stderr)
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return
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self._closed = True
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if _warn:
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self._warn("Implicitly cleaning up {!r}".format(self),
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Warning)
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def __exit__(self, exc, value, tb):
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self.cleanup()
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def __del__(self):
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# Issue a Warning if implicit cleanup needed
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self.cleanup(_warn=True)
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# XXX (ncoghlan): The following code attempts to make
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# this class tolerant of the module nulling out process
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# that happens during CPython interpreter shutdown
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# Alas, it doesn't actually manage it. See issue #10188
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_listdir = staticmethod(_os.listdir)
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_path_join = staticmethod(_os.path.join)
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_isdir = staticmethod(_os.path.isdir)
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_islink = staticmethod(_os.path.islink)
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_remove = staticmethod(_os.remove)
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_rmdir = staticmethod(_os.rmdir)
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_warn = _warnings.warn
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def _rmtree(self, path):
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# Essentially a stripped down version of shutil.rmtree. We can't
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# use globals because they may be None'ed out at shutdown.
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for name in self._listdir(path):
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fullname = self._path_join(path, name)
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try:
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isdir = (self._isdir(fullname) and not
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self._islink(fullname))
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except OSError:
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isdir = False
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if isdir:
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self._rmtree(fullname)
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else:
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try:
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self._remove(fullname)
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except OSError:
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pass
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try:
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self._rmdir(path)
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except OSError:
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pass
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# ======= Compatibility for datasets that care about Python versions ========
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# The following datasets have a /PY3 subdirectory containing
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# a full copy of the data which has been re-encoded or repickled.
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DATA_UPDATES = [("chunkers", "maxent_ne_chunker"),
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("help", "tagsets"),
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("taggers", "maxent_treebank_pos_tagger"),
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("tokenizers", "punkt")]
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_PY3_DATA_UPDATES = [os.path.join(*path_list) for path_list in DATA_UPDATES]
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def add_py3_data(path):
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if PY3:
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for item in _PY3_DATA_UPDATES:
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if item in str(path) and "/PY3" not in str(path):
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pos = path.index(item) + len(item)
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if path[pos:pos + 4] == ".zip":
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pos += 4
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path = path[:pos] + "/PY3" + path[pos:]
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break
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return path
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# for use in adding /PY3 to the second (filename) argument
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# of the file pointers in data.py
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def py3_data(init_func):
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def _decorator(*args, **kwargs):
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args = (args[0], add_py3_data(args[1])) + args[2:]
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return init_func(*args, **kwargs)
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return wraps(init_func)(_decorator)
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# ======= Compatibility layer for __str__ and __repr__ ==========
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def remove_accents(text):
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if isinstance(text, bytes):
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text = text.decode('ascii')
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category = unicodedata.category # this gives a small (~10%) speedup
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return ''.join(
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c for c in unicodedata.normalize('NFKD', text) if category(c) != 'Mn'
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)
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# Select the best transliteration method:
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try:
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# Older versions of Unidecode are licensed under Artistic License;
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# assume an older version is installed.
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from unidecode import unidecode as transliterate
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except ImportError:
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try:
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# text-unidecode implementation is worse than Unidecode
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# implementation so Unidecode is preferred.
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from text_unidecode import unidecode as transliterate
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except ImportError:
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# This transliteration method should be enough
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# for many Western languages.
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transliterate = remove_accents
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def python_2_unicode_compatible(klass):
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"""
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This decorator defines __unicode__ method and fixes
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__repr__ and __str__ methods under Python 2.
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To support Python 2 and 3 with a single code base,
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define __str__ and __repr__ methods returning unicode
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text and apply this decorator to the class.
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Original __repr__ and __str__ would be available
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as unicode_repr and __unicode__ (under both Python 2
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and Python 3).
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"""
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if not issubclass(klass, object):
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raise ValueError("This decorator doesn't work for old-style classes")
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# both __unicode__ and unicode_repr are public because they
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# may be useful in console under Python 2.x
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# if __str__ or __repr__ are not overriden in a subclass,
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# they may be already fixed by this decorator in a parent class
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# and we shouldn't them again
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if not _was_fixed(klass.__str__):
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klass.__unicode__ = klass.__str__
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if not PY3:
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klass.__str__ = _7bit(_transliterated(klass.__unicode__))
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if not _was_fixed(klass.__repr__):
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klass.unicode_repr = klass.__repr__
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if not PY3:
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klass.__repr__ = _7bit(klass.unicode_repr)
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return klass
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def unicode_repr(obj):
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"""
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For classes that was fixed with @python_2_unicode_compatible
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``unicode_repr`` returns ``obj.unicode_repr()``; for unicode strings
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the result is returned without "u" letter (to make output the
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same under Python 2.x and Python 3.x); for other variables
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it is the same as ``repr``.
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"""
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if PY3:
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return repr(obj)
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# Python 2.x
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if hasattr(obj, 'unicode_repr'):
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return obj.unicode_repr()
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if isinstance(obj, text_type):
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return repr(obj)[1:] # strip "u" letter from output
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return repr(obj)
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def _transliterated(method):
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def wrapper(self):
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return transliterate(method(self))
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update_wrapper(wrapper, method, ["__name__", "__doc__"])
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if hasattr(method, "_nltk_compat_7bit"):
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wrapper._nltk_compat_7bit = method._nltk_compat_7bit
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wrapper._nltk_compat_transliterated = True
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return wrapper
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def _7bit(method):
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def wrapper(self):
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return method(self).encode('ascii', 'backslashreplace')
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update_wrapper(wrapper, method, ["__name__", "__doc__"])
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if hasattr(method, "_nltk_compat_transliterated"):
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wrapper._nltk_compat_transliterated = (
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method._nltk_compat_transliterated
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)
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wrapper._nltk_compat_7bit = True
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return wrapper
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def _was_fixed(method):
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return (getattr(method, "_nltk_compat_7bit", False) or
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getattr(method, "_nltk_compat_transliterated", False))
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class Fraction(fractions.Fraction):
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"""
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This is a simplified backwards compatible version of fractions.Fraction
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from Python >=3.5. It adds the `_normalize` parameter such that it does
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not normalize the denominator to the Greatest Common Divisor (gcd) when
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the numerator is 0.
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This is most probably only used by the nltk.translate.bleu_score.py where
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numerator and denominator of the different ngram precisions are mutable.
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But the idea of "mutable" fraction might not be applicable to other usages,
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See http://stackoverflow.com/questions/34561265
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This objects should be deprecated once NLTK stops supporting Python < 3.5
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See https://github.com/nltk/nltk/issues/1330
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"""
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def __new__(cls, numerator=0, denominator=None, _normalize=True):
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cls = super(Fraction, cls).__new__(cls, numerator, denominator)
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# To emulate fraction.Fraction.from_float across Python >=2.7,
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# check that numerator is an integer and denominator is not None.
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if not _normalize and type(numerator) == int and denominator:
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cls._numerator = numerator
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cls._denominator = denominator
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return cls
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