Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/chardet/latin1prober.py: 98%

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, see 

25# <https://www.gnu.org/licenses/>. 

26######################### END LICENSE BLOCK ######################### 

27 

28from typing import List, Union 

29 

30from .charsetprober import CharSetProber 

31from .enums import ProbingState 

32 

33FREQ_CAT_NUM = 4 

34 

35UDF = 0 # undefined 

36OTH = 1 # other 

37ASC = 2 # ascii capital letter 

38ASS = 3 # ascii small letter 

39ACV = 4 # accent capital vowel 

40ACO = 5 # accent capital other 

41ASV = 6 # accent small vowel 

42ASO = 7 # accent small other 

43CLASS_NUM = 8 # total classes 

44 

45# fmt: off 

46Latin1_CharToClass = ( 

47 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 00 - 07 

48 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 08 - 0F 

49 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 10 - 17 

50 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 18 - 1F 

51 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 20 - 27 

52 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 28 - 2F 

53 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 30 - 37 

54 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 38 - 3F 

55 OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC, # 40 - 47 

56 ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, # 48 - 4F 

57 ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, # 50 - 57 

58 ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH, # 58 - 5F 

59 OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS, # 60 - 67 

60 ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, # 68 - 6F 

61 ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, # 70 - 77 

62 ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH, # 78 - 7F 

63 OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH, # 80 - 87 

64 OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF, # 88 - 8F 

65 UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 90 - 97 

66 OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO, # 98 - 9F 

67 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # A0 - A7 

68 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # A8 - AF 

69 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # B0 - B7 

70 OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # B8 - BF 

71 ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO, # C0 - C7 

72 ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV, # C8 - CF 

73 ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH, # D0 - D7 

74 ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO, # D8 - DF 

75 ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO, # E0 - E7 

76 ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV, # E8 - EF 

77 ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH, # F0 - F7 

78 ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO, # F8 - FF 

79) 

80 

81# 0 : illegal 

82# 1 : very unlikely 

83# 2 : normal 

84# 3 : very likely 

85Latin1ClassModel = ( 

86# UDF OTH ASC ASS ACV ACO ASV ASO 

87 0, 0, 0, 0, 0, 0, 0, 0, # UDF 

88 0, 3, 3, 3, 3, 3, 3, 3, # OTH 

89 0, 3, 3, 3, 3, 3, 3, 3, # ASC 

90 0, 3, 3, 3, 1, 1, 3, 3, # ASS 

91 0, 3, 3, 3, 1, 2, 1, 2, # ACV 

92 0, 3, 3, 3, 3, 3, 3, 3, # ACO 

93 0, 3, 1, 3, 1, 1, 1, 3, # ASV 

94 0, 3, 1, 3, 1, 1, 3, 3, # ASO 

95) 

96# fmt: on 

97 

98 

99class Latin1Prober(CharSetProber): 

100 def __init__(self) -> None: 

101 super().__init__() 

102 self._last_char_class = OTH 

103 self._freq_counter: List[int] = [] 

104 self.reset() 

105 

106 def reset(self) -> None: 

107 self._last_char_class = OTH 

108 self._freq_counter = [0] * FREQ_CAT_NUM 

109 super().reset() 

110 

111 @property 

112 def charset_name(self) -> str: 

113 return "ISO-8859-1" 

114 

115 @property 

116 def language(self) -> str: 

117 return "" 

118 

119 def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState: 

120 byte_str = self.remove_xml_tags(byte_str) 

121 for c in byte_str: 

122 char_class = Latin1_CharToClass[c] 

123 freq = Latin1ClassModel[(self._last_char_class * CLASS_NUM) + char_class] 

124 if freq == 0: 

125 self._state = ProbingState.NOT_ME 

126 break 

127 self._freq_counter[freq] += 1 

128 self._last_char_class = char_class 

129 

130 return self.state 

131 

132 def get_confidence(self) -> float: 

133 if self.state == ProbingState.NOT_ME: 

134 return 0.01 

135 

136 total = sum(self._freq_counter) 

137 confidence = ( 

138 0.0 

139 if total < 0.01 

140 else (self._freq_counter[3] - self._freq_counter[1] * 20.0) / total 

141 ) 

142 confidence = max(confidence, 0.0) 

143 # lower the confidence of latin1 so that other more accurate 

144 # detector can take priority. 

145 confidence *= 0.73 

146 return confidence