guppy_basecaller: env/lib/python3.7/site-packages/chardet/hebrewprober.py comparison

comparison env/lib/python3.7/site-packages/chardet/hebrewprober.py @ 0:26e78fe6e8c4 draft

"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"

author	shellac
date	Sat, 02 May 2020 07:14:21 -0400
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--1:000000000000
+:26e78fe6e8c4
+######################## BEGIN LICENSE BLOCK ########################
+# The Original Code is Mozilla Universal charset detector code.
+#
+# The Initial Developer of the Original Code is
+#          Shy Shalom
+# Portions created by the Initial Developer are Copyright (C) 2005
+# the Initial Developer. All Rights Reserved.
+#
+# Contributor(s):
+#   Mark Pilgrim - port to Python
+#
+# 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 #########################
+from .charsetprober import CharSetProber
+from .enums import ProbingState
+# This prober doesn't actually recognize a language or a charset.
+# It is a helper prober for the use of the Hebrew model probers
+### General ideas of the Hebrew charset recognition ###
+#
+# Four main charsets exist in Hebrew:
+# "ISO-8859-8" - Visual Hebrew
+# "windows-1255" - Logical Hebrew
+# "ISO-8859-8-I" - Logical Hebrew
+# "x-mac-hebrew" - ?? Logical Hebrew ??
+#
+# Both "ISO" charsets use a completely identical set of code points, whereas
+# "windows-1255" and "x-mac-hebrew" are two different proper supersets of
+# these code points. windows-1255 defines additional characters in the range
+# 0x80-0x9F as some misc punctuation marks as well as some Hebrew-specific
+# diacritics and additional 'Yiddish' ligature letters in the range 0xc0-0xd6.
+# x-mac-hebrew defines similar additional code points but with a different
+# mapping.
+#
+# As far as an average Hebrew text with no diacritics is concerned, all four
+# charsets are identical with respect to code points. Meaning that for the
+# main Hebrew alphabet, all four map the same values to all 27 Hebrew letters
+# (including final letters).
+#
+# The dominant difference between these charsets is their directionality.
+# "Visual" directionality means that the text is ordered as if the renderer is
+# not aware of a BIDI rendering algorithm. The renderer sees the text and
+# draws it from left to right. The text itself when ordered naturally is read
+# backwards. A buffer of Visual Hebrew generally looks like so:
+# "[last word of first line spelled backwards] [whole line ordered backwards
+# and spelled backwards] [first word of first line spelled backwards]
+# [end of line] [last word of second line] ... etc' "
+# adding punctuation marks, numbers and English text to visual text is
+# naturally also "visual" and from left to right.
+#
+# "Logical" directionality means the text is ordered "naturally" according to
+# the order it is read. It is the responsibility of the renderer to display
+# the text from right to left. A BIDI algorithm is used to place general
+# punctuation marks, numbers and English text in the text.
+#
+# Texts in x-mac-hebrew are almost impossible to find on the Internet. From
+# what little evidence I could find, it seems that its general directionality
+# is Logical.
+#
+# To sum up all of the above, the Hebrew probing mechanism knows about two
+# charsets:
+# Visual Hebrew - "ISO-8859-8" - backwards text - Words and sentences are
+#    backwards while line order is natural. For charset recognition purposes
+#    the line order is unimportant (In fact, for this implementation, even
+#    word order is unimportant).
+# Logical Hebrew - "windows-1255" - normal, naturally ordered text.
+#
+# "ISO-8859-8-I" is a subset of windows-1255 and doesn't need to be
+#    specifically identified.
+# "x-mac-hebrew" is also identified as windows-1255. A text in x-mac-hebrew
+#    that contain special punctuation marks or diacritics is displayed with
+#    some unconverted characters showing as question marks. This problem might
+#    be corrected using another model prober for x-mac-hebrew. Due to the fact
+#    that x-mac-hebrew texts are so rare, writing another model prober isn't
+#    worth the effort and performance hit.
+#
+#### The Prober ####
+#
+# The prober is divided between two SBCharSetProbers and a HebrewProber,
+# all of which are managed, created, fed data, inquired and deleted by the
+# SBCSGroupProber. The two SBCharSetProbers identify that the text is in
+# fact some kind of Hebrew, Logical or Visual. The final decision about which
+# one is it is made by the HebrewProber by combining final-letter scores
+# with the scores of the two SBCharSetProbers to produce a final answer.
+#
+# The SBCSGroupProber is responsible for stripping the original text of HTML
+# tags, English characters, numbers, low-ASCII punctuation characters, spaces
+# and new lines. It reduces any sequence of such characters to a single space.
+# The buffer fed to each prober in the SBCS group prober is pure text in
+# high-ASCII.
+# The two SBCharSetProbers (model probers) share the same language model:
+# Win1255Model.
+# The first SBCharSetProber uses the model normally as any other
+# SBCharSetProber does, to recognize windows-1255, upon which this model was
+# built. The second SBCharSetProber is told to make the pair-of-letter
+# lookup in the language model backwards. This in practice exactly simulates
+# a visual Hebrew model using the windows-1255 logical Hebrew model.
+#
+# The HebrewProber is not using any language model. All it does is look for
+# final-letter evidence suggesting the text is either logical Hebrew or visual
+# Hebrew. Disjointed from the model probers, the results of the HebrewProber
+# alone are meaningless. HebrewProber always returns 0.00 as confidence
+# since it never identifies a charset by itself. Instead, the pointer to the
+# HebrewProber is passed to the model probers as a helper "Name Prober".
+# When the Group prober receives a positive identification from any prober,
+# it asks for the name of the charset identified. If the prober queried is a
+# Hebrew model prober, the model prober forwards the call to the
+# HebrewProber to make the final decision. In the HebrewProber, the
+# decision is made according to the final-letters scores maintained and Both
+# model probers scores. The answer is returned in the form of the name of the
+# charset identified, either "windows-1255" or "ISO-8859-8".
+class HebrewProber(CharSetProber):
+# windows-1255 / ISO-8859-8 code points of interest
+FINAL_KAF = 0xea
+NORMAL_KAF = 0xeb
+FINAL_MEM = 0xed
+NORMAL_MEM = 0xee
+FINAL_NUN = 0xef
+NORMAL_NUN = 0xf0
+FINAL_PE = 0xf3
+NORMAL_PE = 0xf4
+FINAL_TSADI = 0xf5
+NORMAL_TSADI = 0xf6
+# Minimum Visual vs Logical final letter score difference.
+# If the difference is below this, don't rely solely on the final letter score
+# distance.
+MIN_FINAL_CHAR_DISTANCE = 5
+# Minimum Visual vs Logical model score difference.
+# If the difference is below this, don't rely at all on the model score
+# distance.
+MIN_MODEL_DISTANCE = 0.01
+VISUAL_HEBREW_NAME = "ISO-8859-8"
+LOGICAL_HEBREW_NAME = "windows-1255"
+def __init__(self):
+super(HebrewProber, self).__init__()
+self._final_char_logical_score = None
+self._final_char_visual_score = None
+self._prev = None
+self._before_prev = None
+self._logical_prober = None
+self._visual_prober = None
+self.reset()
+def reset(self):
+self._final_char_logical_score = 0
+self._final_char_visual_score = 0
+# The two last characters seen in the previous buffer,
+# mPrev and mBeforePrev are initialized to space in order to simulate
+# a word delimiter at the beginning of the data
+self._prev = ' '
+self._before_prev = ' '
+# These probers are owned by the group prober.
+def set_model_probers(self, logicalProber, visualProber):
+self._logical_prober = logicalProber
+self._visual_prober = visualProber
+def is_final(self, c):
+return c in [self.FINAL_KAF, self.FINAL_MEM, self.FINAL_NUN,
+self.FINAL_PE, self.FINAL_TSADI]
+def is_non_final(self, c):
+# The normal Tsadi is not a good Non-Final letter due to words like
+# 'lechotet' (to chat) containing an apostrophe after the tsadi. This
+# apostrophe is converted to a space in FilterWithoutEnglishLetters
+# causing the Non-Final tsadi to appear at an end of a word even
+# though this is not the case in the original text.
+# The letters Pe and Kaf rarely display a related behavior of not being
+# a good Non-Final letter. Words like 'Pop', 'Winamp' and 'Mubarak'
+# for example legally end with a Non-Final Pe or Kaf. However, the
+# benefit of these letters as Non-Final letters outweighs the damage
+# since these words are quite rare.
+return c in [self.NORMAL_KAF, self.NORMAL_MEM,
+self.NORMAL_NUN, self.NORMAL_PE]
+def feed(self, byte_str):
+# Final letter analysis for logical-visual decision.
+# Look for evidence that the received buffer is either logical Hebrew
+# or visual Hebrew.
+# The following cases are checked:
+# 1) A word longer than 1 letter, ending with a final letter. This is
+#    an indication that the text is laid out "naturally" since the
+#    final letter really appears at the end. +1 for logical score.
+# 2) A word longer than 1 letter, ending with a Non-Final letter. In
+#    normal Hebrew, words ending with Kaf, Mem, Nun, Pe or Tsadi,
+#    should not end with the Non-Final form of that letter. Exceptions
+#    to this rule are mentioned above in isNonFinal(). This is an
+#    indication that the text is laid out backwards. +1 for visual
+#    score
+# 3) A word longer than 1 letter, starting with a final letter. Final
+#    letters should not appear at the beginning of a word. This is an
+#    indication that the text is laid out backwards. +1 for visual
+#    score.
+#
+# The visual score and logical score are accumulated throughout the
+# text and are finally checked against each other in GetCharSetName().
+# No checking for final letters in the middle of words is done since
+# that case is not an indication for either Logical or Visual text.
+#
+# We automatically filter out all 7-bit characters (replace them with
+# spaces) so the word boundary detection works properly. [MAP]
+if self.state == ProbingState.NOT_ME:
+# Both model probers say it's not them. No reason to continue.
+return ProbingState.NOT_ME
+byte_str = self.filter_high_byte_only(byte_str)
+for cur in byte_str:
+if cur == ' ':
+# We stand on a space - a word just ended
+if self._before_prev != ' ':
+# next-to-last char was not a space so self._prev is not a
+# 1 letter word
+if self.is_final(self._prev):
+# case (1) [-2:not space][-1:final letter][cur:space]
+self._final_char_logical_score += 1
+elif self.is_non_final(self._prev):
+# case (2) [-2:not space][-1:Non-Final letter][
+#  cur:space]
+self._final_char_visual_score += 1
+else:
+# Not standing on a space
+if ((self._before_prev == ' ') and
+(self.is_final(self._prev)) and (cur != ' ')):
+# case (3) [-2:space][-1:final letter][cur:not space]
+self._final_char_visual_score += 1
+self._before_prev = self._prev
+self._prev = cur
+# Forever detecting, till the end or until both model probers return
+# ProbingState.NOT_ME (handled above)
+return ProbingState.DETECTING
+@property
+def charset_name(self):
+# Make the decision: is it Logical or Visual?
+# If the final letter score distance is dominant enough, rely on it.
+finalsub = self._final_char_logical_score - self._final_char_visual_score
+if finalsub >= self.MIN_FINAL_CHAR_DISTANCE:
+return self.LOGICAL_HEBREW_NAME
+if finalsub <= -self.MIN_FINAL_CHAR_DISTANCE:
+return self.VISUAL_HEBREW_NAME
+# It's not dominant enough, try to rely on the model scores instead.
+modelsub = (self._logical_prober.get_confidence()
+- self._visual_prober.get_confidence())
+if modelsub > self.MIN_MODEL_DISTANCE:
+return self.LOGICAL_HEBREW_NAME
+if modelsub < -self.MIN_MODEL_DISTANCE:
+return self.VISUAL_HEBREW_NAME
+# Still no good, back to final letter distance, maybe it'll save the
+# day.
+if finalsub < 0.0:
+return self.VISUAL_HEBREW_NAME
+# (finalsub > 0 - Logical) or (don't know what to do) default to
+# Logical.
+return self.LOGICAL_HEBREW_NAME
+@property
+def language(self):
+return 'Hebrew'
+@property
+def state(self):
+# Remain active as long as any of the model probers are active.
+if (self._logical_prober.state == ProbingState.NOT_ME) and \
+(self._visual_prober.state == ProbingState.NOT_ME):
+return ProbingState.NOT_ME
+return ProbingState.DETECTING

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comparison env/lib/python3.7/site-packages/chardet/hebrewprober.py @ 0:26e78fe6e8c4 draft