source: titan/mediathek/localhoster/lib/requests/chardet/latin1prober.py @ 44466

Last change on this file since 44466 was 44466, checked in by obi, 4 years ago

fix cloudflare

File size: 5.2 KB
Line 
1######################## BEGIN LICENSE BLOCK ########################
2# The Original Code is Mozilla Universal charset detector code.
3#
4# The Initial Developer of the Original Code is
5# Netscape Communications Corporation.
6# Portions created by the Initial Developer are Copyright (C) 2001
7# the Initial Developer. All Rights Reserved.
8#
9# Contributor(s):
10#   Mark Pilgrim - port to Python
11#   Shy Shalom - original C code
12#
13# This library is free software; you can redistribute it and/or
14# modify it under the terms of the GNU Lesser General Public
15# License as published by the Free Software Foundation; either
16# version 2.1 of the License, or (at your option) any later version.
17#
18# This library is distributed in the hope that it will be useful,
19# but WITHOUT ANY WARRANTY; without even the implied warranty of
20# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21# Lesser General Public License for more details.
22#
23# You should have received a copy of the GNU Lesser General Public
24# License along with this library; if not, write to the Free Software
25# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
26# 02110-1301  USA
27######################### END LICENSE BLOCK #########################
28
29from .charsetprober import CharSetProber
30from .enums import ProbingState
31
32FREQ_CAT_NUM = 4
33
34UDF = 0  # undefined
35OTH = 1  # other
36ASC = 2  # ascii capital letter
37ASS = 3  # ascii small letter
38ACV = 4  # accent capital vowel
39ACO = 5  # accent capital other
40ASV = 6  # accent small vowel
41ASO = 7  # accent small other
42CLASS_NUM = 8  # total classes
43
44Latin1_CharToClass = (
45    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 00 - 07
46    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 08 - 0F
47    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 10 - 17
48    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 18 - 1F
49    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 20 - 27
50    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 28 - 2F
51    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 30 - 37
52    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 38 - 3F
53    OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   # 40 - 47
54    ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   # 48 - 4F
55    ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   # 50 - 57
56    ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH,   # 58 - 5F
57    OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   # 60 - 67
58    ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   # 68 - 6F
59    ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   # 70 - 77
60    ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH,   # 78 - 7F
61    OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH,   # 80 - 87
62    OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF,   # 88 - 8F
63    UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # 90 - 97
64    OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO,   # 98 - 9F
65    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # A0 - A7
66    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # A8 - AF
67    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # B0 - B7
68    OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   # B8 - BF
69    ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO,   # C0 - C7
70    ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV,   # C8 - CF
71    ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH,   # D0 - D7
72    ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO,   # D8 - DF
73    ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO,   # E0 - E7
74    ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV,   # E8 - EF
75    ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH,   # F0 - F7
76    ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO,   # F8 - FF
77)
78
79# 0 : illegal
80# 1 : very unlikely
81# 2 : normal
82# 3 : very likely
83Latin1ClassModel = (
84# UDF OTH ASC ASS ACV ACO ASV ASO
85    0,  0,  0,  0,  0,  0,  0,  0,  # UDF
86    0,  3,  3,  3,  3,  3,  3,  3,  # OTH
87    0,  3,  3,  3,  3,  3,  3,  3,  # ASC
88    0,  3,  3,  3,  1,  1,  3,  3,  # ASS
89    0,  3,  3,  3,  1,  2,  1,  2,  # ACV
90    0,  3,  3,  3,  3,  3,  3,  3,  # ACO
91    0,  3,  1,  3,  1,  1,  1,  3,  # ASV
92    0,  3,  1,  3,  1,  1,  3,  3,  # ASO
93)
94
95
96class Latin1Prober(CharSetProber):
97    def __init__(self):
98        super(Latin1Prober, self).__init__()
99        self._last_char_class = None
100        self._freq_counter = None
101        self.reset()
102
103    def reset(self):
104        self._last_char_class = OTH
105        self._freq_counter = [0] * FREQ_CAT_NUM
106        CharSetProber.reset(self)
107
108    @property
109    def charset_name(self):
110        return "ISO-8859-1"
111
112    @property
113    def language(self):
114        return ""
115
116    def feed(self, byte_str):
117        byte_str = self.filter_with_english_letters(byte_str)
118        for c in byte_str:
119            char_class = Latin1_CharToClass[c]
120            freq = Latin1ClassModel[(self._last_char_class * CLASS_NUM)
121                                    + char_class]
122            if freq == 0:
123                self._state = ProbingState.NOT_ME
124                break
125            self._freq_counter[freq] += 1
126            self._last_char_class = char_class
127
128        return self.state
129
130    def get_confidence(self):
131        if self.state == ProbingState.NOT_ME:
132            return 0.01
133
134        total = sum(self._freq_counter)
135        if total < 0.01:
136            confidence = 0.0
137        else:
138            confidence = ((self._freq_counter[3] - self._freq_counter[1] * 20.0)
139                          / total)
140        if confidence < 0.0:
141            confidence = 0.0
142        # lower the confidence of latin1 so that other more accurate
143        # detector can take priority.
144        confidence = confidence * 0.73
145        return confidence
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