/usr/lib/python2.7/dist-packages/chardet/charsetprober.py is in python-chardet 3.0.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 | ######################## BEGIN LICENSE BLOCK ########################
# The Original Code is Mozilla Universal charset detector code.
#
# The Initial Developer of the Original Code is
# Netscape Communications Corporation.
# Portions created by the Initial Developer are Copyright (C) 2001
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Mark Pilgrim - port to Python
# Shy Shalom - original C code
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
# 02110-1301 USA
######################### END LICENSE BLOCK #########################
import logging
import re
from .enums import ProbingState
class CharSetProber(object):
SHORTCUT_THRESHOLD = 0.95
def __init__(self, lang_filter=None):
self._state = None
self.lang_filter = lang_filter
self.logger = logging.getLogger(__name__)
def reset(self):
self._state = ProbingState.DETECTING
@property
def charset_name(self):
return None
def feed(self, buf):
pass
@property
def state(self):
return self._state
def get_confidence(self):
return 0.0
@staticmethod
def filter_high_byte_only(buf):
buf = re.sub(b'([\x00-\x7F])+', b' ', buf)
return buf
@staticmethod
def filter_international_words(buf):
"""
We define three types of bytes:
alphabet: english alphabets [a-zA-Z]
international: international characters [\x80-\xFF]
marker: everything else [^a-zA-Z\x80-\xFF]
The input buffer can be thought to contain a series of words delimited
by markers. This function works to filter all words that contain at
least one international character. All contiguous sequences of markers
are replaced by a single space ascii character.
This filter applies to all scripts which do not use English characters.
"""
filtered = bytearray()
# This regex expression filters out only words that have at-least one
# international character. The word may include one marker character at
# the end.
words = re.findall(b'[a-zA-Z]*[\x80-\xFF]+[a-zA-Z]*[^a-zA-Z\x80-\xFF]?',
buf)
for word in words:
filtered.extend(word[:-1])
# If the last character in the word is a marker, replace it with a
# space as markers shouldn't affect our analysis (they are used
# similarly across all languages and may thus have similar
# frequencies).
last_char = word[-1:]
if not last_char.isalpha() and last_char < b'\x80':
last_char = b' '
filtered.extend(last_char)
return filtered
@staticmethod
def filter_with_english_letters(buf):
"""
Returns a copy of ``buf`` that retains only the sequences of English
alphabet and high byte characters that are not between <> characters.
Also retains English alphabet and high byte characters immediately
before occurrences of >.
This filter can be applied to all scripts which contain both English
characters and extended ASCII characters, but is currently only used by
``Latin1Prober``.
"""
filtered = bytearray()
in_tag = False
prev = 0
for curr in range(len(buf)):
# Slice here to get bytes instead of an int with Python 3
buf_char = buf[curr:curr + 1]
# Check if we're coming out of or entering an HTML tag
if buf_char == b'>':
in_tag = False
elif buf_char == b'<':
in_tag = True
# If current character is not extended-ASCII and not alphabetic...
if buf_char < b'\x80' and not buf_char.isalpha():
# ...and we're not in a tag
if curr > prev and not in_tag:
# Keep everything after last non-extended-ASCII,
# non-alphabetic character
filtered.extend(buf[prev:curr])
# Output a space to delimit stretch we kept
filtered.extend(b' ')
prev = curr + 1
# If we're not in a tag...
if not in_tag:
# Keep everything after last non-extended-ASCII, non-alphabetic
# character
filtered.extend(buf[prev:])
return filtered
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