Mercurial > repos > shellac > guppy_basecaller
diff env/lib/python3.7/site-packages/chardet/charsetprober.py @ 0:26e78fe6e8c4 draft
"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
author | shellac |
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date | Sat, 02 May 2020 07:14:21 -0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.7/site-packages/chardet/charsetprober.py Sat May 02 07:14:21 2020 -0400 @@ -0,0 +1,145 @@ +######################## 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