| Class Hierarchy for chardet | |
| =========================== | |
| Universal Detector | |
| ------------------ | |
| Has a list of probers. | |
| CharSetProber | |
| ------------- | |
| Mostly abstract parent class. | |
| CharSetGroupProber | |
| ------------------ | |
| Runs a bunch of related probers at the same time and decides which is best. | |
| SBCSGroupProber | |
| --------------- | |
| SBCS = Single-ByteCharSet. Runs a bunch of SingleByteCharSetProbers. Always | |
| contains the same SingleByteCharSetProbers. | |
| SingleByteCharSetProber | |
| ----------------------- | |
| A CharSetProber that is used for detecting single-byte encodings by using | |
| a "precedence matrix" (i.e., a character bigram model). | |
| MBCSGroupProber | |
| --------------- | |
| Runs a bunch of MultiByteCharSetProbers. It also uses a UTF8Prober, which is | |
| essentially a MultiByteCharSetProber that only has a state machine. Always | |
| contains the same MultiByteCharSetProbers. | |
| MultiByteCharSetProber | |
| ---------------------- | |
| A CharSetProber that uses both a character unigram model (or "character | |
| distribution analysis") and an independent state machine for trying to | |
| detect and encoding. | |
| CodingStateMachine | |
| ------------------ | |
| Used for "coding scheme" detection, where we just look for either invalid | |
| byte sequences or sequences that only occur for that particular encoding. | |
| CharDistributionAnalysis | |
| ------------------------ | |
| Used for character unigram distribution encoding detection. Takes a mapping | |
| from characters to a "frequency order" (i.e., what frequency rank that byte has | |
| in the given encoding) and a "typical distribution ratio", which is the number | |
| of occurrences of the 512 most frequently used characters divided by the number | |
| of occurrences of the rest of the characters for a typical document. | |
| The "characters" in this case are 2-byte sequences and they are first converted | |
| to an "order" (name comes from ord() function, I believe). This "order" is used | |
| to index into the frequency order table to determine the frequency rank of that | |
| byte sequence. The reason this extra step is necessary is that the frequency | |
| rank table is language-specific (and not encoding-specific). | |
| What's where | |
| ============ | |
| Bigram files | |
| ------------ | |
| - ``hebrewprober.py`` | |
| - ``jpcntxprober.py`` | |
| - ``langbulgarianmodel.py`` | |
| - ``langcyrillicmodel.py`` | |
| - ``langgreekmodel.py`` | |
| - ``langhebrewmodel.py`` | |
| - ``langhungarianmodel.py`` | |
| - ``langthaimodel.py`` | |
| - ``latin1prober.py`` | |
| - ``sbcharsetprober.py`` | |
| - ``sbcsgroupprober.py`` | |
| Coding Scheme files | |
| ------------------- | |
| - ``escprober.py`` | |
| - ``escsm.py`` | |
| - ``utf8prober.py`` | |
| - ``codingstatemachine.py`` | |
| - ``mbcssmprober.py`` | |
| Unigram files | |
| ------------- | |
| - ``big5freqprober.py`` | |
| - ``chardistribution.py`` | |
| - ``euckrfreqprober.py`` | |
| - ``euctwfreqprober.py`` | |
| - ``gb2312freqprober.py`` | |
| - ``jisfreqprober.py`` | |
| Multibyte probers | |
| ----------------- | |
| - ``big5prober.py`` | |
| - ``cp949prober.py`` | |
| - ``eucjpprober.py`` | |
| - ``euckrprober.py`` | |
| - ``euctwprober.py`` | |
| - ``gb2312prober.py`` | |
| - ``mbcharsetprober.py`` | |
| - ``mbcsgroupprober.py`` | |
| - ``sjisprober.py`` | |
| Misc files | |
| ---------- | |
| - ``__init__.py`` (currently has ``detect`` function in it) | |
| - ``compat.py`` | |
| - ``enums.py`` | |
| - ``universaldetector.py`` | |
| - ``version.py`` | |
| Useful links | |
| ============ | |
| This is just a collection of information that I've found useful or thought | |
| might be useful in the future: | |
| - `BOM by Encoding`_ | |
| - `A Composite Approach to Language/Encoding Detection`_ | |
| - `What Every Programmer Absolutely...`_ | |
| - The actual `source`_ | |
| .. _BOM by Encoding: | |
| https://en.wikipedia.org/wiki/Byte_order_mark#Byte_order_marks_by_encoding | |
| .. _A Composite Approach to Language/Encoding Detection: | |
| http://www-archive.mozilla.org/projects/intl/UniversalCharsetDetection.html | |
| .. _What Every Programmer Absolutely...: http://kunststube.net/encoding/ | |
| .. _source: https://dxr.mozilla.org/mozilla/source/intl/chardet/ | |