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# -*- coding: utf-8 -*-
# Natural Language Toolkit: Compatibility
#
# Copyright (C) 2001-2019 NLTK Project
#
# URL: <http://nltk.org/>
# For license information, see LICENSE.TXT
from __future__ import absolute_import, print_function
import os
import sys
from functools import update_wrapper, wraps
import fractions
import unicodedata
from six import string_types, text_type
# Python 2/3 compatibility layer. Based on six.
PY3 = sys.version_info[0] == 3
if PY3:
def get_im_class(meth):
return meth.__self__.__class__
import io
StringIO = io.StringIO
BytesIO = io.BytesIO
from datetime import timezone
UTC = timezone.utc
from tempfile import TemporaryDirectory
else:
def get_im_class(meth):
return meth.im_class
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
BytesIO = StringIO
from datetime import tzinfo, timedelta
ZERO = timedelta(0)
HOUR = timedelta(hours=1)
# A UTC class for python 2.7
class UTC(tzinfo):
"""UTC"""
def utcoffset(self, dt):
return ZERO
def tzname(self, dt):
return "UTC"
def dst(self, dt):
return ZERO
UTC = UTC()
import csv
import codecs
import cStringIO
class UnicodeWriter:
"""
A CSV writer which will write rows to CSV file "f",
which is encoded in the given encoding.
see https://docs.python.org/2/library/csv.html
"""
def __init__(
self, f, dialect=csv.excel, encoding="utf-8", errors='replace', **kwds
):
# Redirect output to a queue
self.queue = cStringIO.StringIO()
self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
self.stream = f
encoder_cls = codecs.getincrementalencoder(encoding)
self.encoder = encoder_cls(errors=errors)
def encode(self, data):
if isinstance(data, string_types):
return data.encode("utf-8")
else:
return data
def writerow(self, row):
self.writer.writerow([self.encode(s) for s in row])
# Fetch UTF-8 output from the queue ...
data = self.queue.getvalue()
data = data.decode("utf-8")
# ... and reencode it into the target encoding
data = self.encoder.encode(data, 'replace')
# write to the target stream
self.stream.write(data)
# empty queue
self.queue.truncate(0)
import warnings as _warnings
import os as _os
from tempfile import mkdtemp
class TemporaryDirectory(object):
"""Create and return a temporary directory. This has the same
behavior as mkdtemp but can be used as a context manager. For
example:
with TemporaryDirectory() as tmpdir:
...
Upon exiting the context, the directory and everything contained
in it are removed.
http://stackoverflow.com/questions/19296146/tempfile-temporarydirectory-context-manager-in-python-2-7
"""
def __init__(self, suffix="", prefix="tmp", dir=None):
self._closed = False
self.name = None # Handle mkdtemp raising an exception
self.name = mkdtemp(suffix, prefix, dir)
def __repr__(self):
return "<{} {!r}>".format(self.__class__.__name__, self.name)
def __enter__(self):
return self.name
def cleanup(self, _warn=False):
if self.name and not self._closed:
try:
self._rmtree(self.name)
except (TypeError, AttributeError) as ex:
# Issue #10188: Emit a warning on stderr
# if the directory could not be cleaned
# up due to missing globals
if "None" not in str(ex):
raise
print(
"ERROR: {!r} while cleaning up {!r}".format(ex, self),
file=sys.stderr,
)
return
self._closed = True
if _warn:
self._warn("Implicitly cleaning up {!r}".format(self), Warning)
def __exit__(self, exc, value, tb):
self.cleanup()
def __del__(self):
# Issue a Warning if implicit cleanup needed
self.cleanup(_warn=True)
# XXX (ncoghlan): The following code attempts to make
# this class tolerant of the module nulling out process
# that happens during CPython interpreter shutdown
# Alas, it doesn't actually manage it. See issue #10188
_listdir = staticmethod(_os.listdir)
_path_join = staticmethod(_os.path.join)
_isdir = staticmethod(_os.path.isdir)
_islink = staticmethod(_os.path.islink)
_remove = staticmethod(_os.remove)
_rmdir = staticmethod(_os.rmdir)
_warn = _warnings.warn
def _rmtree(self, path):
# Essentially a stripped down version of shutil.rmtree. We can't
# use globals because they may be None'ed out at shutdown.
for name in self._listdir(path):
fullname = self._path_join(path, name)
try:
isdir = self._isdir(fullname) and not self._islink(fullname)
except OSError:
isdir = False
if isdir:
self._rmtree(fullname)
else:
try:
self._remove(fullname)
except OSError:
pass
try:
self._rmdir(path)
except OSError:
pass
# ======= Compatibility for datasets that care about Python versions ========
# The following datasets have a /PY3 subdirectory containing
# a full copy of the data which has been re-encoded or repickled.
DATA_UPDATES = [
("chunkers", "maxent_ne_chunker"),
("help", "tagsets"),
("taggers", "maxent_treebank_pos_tagger"),
("tokenizers", "punkt"),
]
_PY3_DATA_UPDATES = [os.path.join(*path_list) for path_list in DATA_UPDATES]
def add_py3_data(path):
if PY3:
for item in _PY3_DATA_UPDATES:
if item in str(path) and "/PY3" not in str(path):
pos = path.index(item) + len(item)
if path[pos : pos + 4] == ".zip":
pos += 4
path = path[:pos] + "/PY3" + path[pos:]
break
return path
# for use in adding /PY3 to the second (filename) argument
# of the file pointers in data.py
def py3_data(init_func):
def _decorator(*args, **kwargs):
args = (args[0], add_py3_data(args[1])) + args[2:]
return init_func(*args, **kwargs)
return wraps(init_func)(_decorator)
# ======= Compatibility layer for __str__ and __repr__ ==========
def remove_accents(text):
if isinstance(text, bytes):
text = text.decode('ascii')
category = unicodedata.category # this gives a small (~10%) speedup
return ''.join(
c for c in unicodedata.normalize('NFKD', text) if category(c) != 'Mn'
)
# Select the best transliteration method:
try:
# Older versions of Unidecode are licensed under Artistic License;
# assume an older version is installed.
from unidecode import unidecode as transliterate
except ImportError:
try:
# text-unidecode implementation is worse than Unidecode
# implementation so Unidecode is preferred.
from text_unidecode import unidecode as transliterate
except ImportError:
# This transliteration method should be enough
# for many Western languages.
transliterate = remove_accents
def python_2_unicode_compatible(klass):
"""
This decorator defines __unicode__ method and fixes
__repr__ and __str__ methods under Python 2.
To support Python 2 and 3 with a single code base,
define __str__ and __repr__ methods returning unicode
text and apply this decorator to the class.
Original __repr__ and __str__ would be available
as unicode_repr and __unicode__ (under both Python 2
and Python 3).
"""
if not issubclass(klass, object):
raise ValueError("This decorator doesn't work for old-style classes")
# both __unicode__ and unicode_repr are public because they
# may be useful in console under Python 2.x
# if __str__ or __repr__ are not overriden in a subclass,
# they may be already fixed by this decorator in a parent class
# and we shouldn't them again
if not _was_fixed(klass.__str__):
klass.__unicode__ = klass.__str__
if not PY3:
klass.__str__ = _7bit(_transliterated(klass.__unicode__))
if not _was_fixed(klass.__repr__):
klass.unicode_repr = klass.__repr__
if not PY3:
klass.__repr__ = _7bit(klass.unicode_repr)
return klass
def unicode_repr(obj):
"""
For classes that was fixed with @python_2_unicode_compatible
``unicode_repr`` returns ``obj.unicode_repr()``; for unicode strings
the result is returned without "u" letter (to make output the
same under Python 2.x and Python 3.x); for other variables
it is the same as ``repr``.
"""
if PY3:
return repr(obj)
# Python 2.x
if hasattr(obj, 'unicode_repr'):
return obj.unicode_repr()
if isinstance(obj, text_type):
return repr(obj)[1:] # strip "u" letter from output
return repr(obj)
def _transliterated(method):
def wrapper(self):
return transliterate(method(self))
update_wrapper(wrapper, method, ["__name__", "__doc__"])
if hasattr(method, "_nltk_compat_7bit"):
wrapper._nltk_compat_7bit = method._nltk_compat_7bit
wrapper._nltk_compat_transliterated = True
return wrapper
def _7bit(method):
def wrapper(self):
return method(self).encode('ascii', 'backslashreplace')
update_wrapper(wrapper, method, ["__name__", "__doc__"])
if hasattr(method, "_nltk_compat_transliterated"):
wrapper._nltk_compat_transliterated = method._nltk_compat_transliterated
wrapper._nltk_compat_7bit = True
return wrapper
def _was_fixed(method):
return getattr(method, "_nltk_compat_7bit", False) or getattr(
method, "_nltk_compat_transliterated", False
)
class Fraction(fractions.Fraction):
"""
This is a simplified backwards compatible version of fractions.Fraction
from Python >=3.5. It adds the `_normalize` parameter such that it does
not normalize the denominator to the Greatest Common Divisor (gcd) when
the numerator is 0.
This is most probably only used by the nltk.translate.bleu_score.py where
numerator and denominator of the different ngram precisions are mutable.
But the idea of "mutable" fraction might not be applicable to other usages,
See http://stackoverflow.com/questions/34561265
This objects should be deprecated once NLTK stops supporting Python < 3.5
See https://github.com/nltk/nltk/issues/1330
"""
def __new__(cls, numerator=0, denominator=None, _normalize=True):
cls = super(Fraction, cls).__new__(cls, numerator, denominator)
# To emulate fraction.Fraction.from_float across Python >=2.7,
# check that numerator is an integer and denominator is not None.
if not _normalize and type(numerator) == int and denominator:
cls._numerator = numerator
cls._denominator = denominator
return cls