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encdet.py
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<protect>#!/usr/bin/env python
# -*- encoding: japanese.ms932 -*-
# encdet.py - An encoding detector
# by Yusuke Shinyama
# * public domain *
import sys, re
## EncodingRecognizer
## - a finite automaton which receives octets
##
class EncodingRecognizer:
SCORE_DEFAULT = 0.5
DEATH_PENALTY = -100
GIVEUP_THRESHOLD = -1000
# character sets: must be exclusive!
CHARSET = [
# zenkaku-kana
(1.5, re.compile(u"[ぁ-ん]"), 0x01),
(1.5, re.compile(u"[ァ-ヴ]"), 0x02),
(1.0, re.compile(u"[ーヽヾゝゞ]"), 0x03),
# hankaku latin
(1.2, re.compile(u"[a-zA-Z0-9]"), 0x04),
(0.0, re.compile(u"[\u00c0-\u00ff]"), 0x04),
# hankaku-kana
(0.8, re.compile(u"[\uff66-\uff9d]"), 0x08),
# zenkaku-alphanum
(1.2, re.compile(u"[Ａ-Ｚａ-ｚ０-９]"), 0x10),
# kanji
(1.0, re.compile(u"[\u4e00-\u9fff]"), 0x20),
]
def __init__(self, encoding):
self.encoding = encoding
self.ch = ""
self.state = 1
self.partial_score = 0.0
self.total_score = 0.0
self.chunk_type = 0
return
def __repr__(self):
return "<EncodingRecognizer: %s, state=%d, chunk_type=%s, partial_score=%d, total_score=%d>" % \
(self.encoding, self.state, self.chunk_type, self.partial_score, self.total_score)
def die(self):
#print "died:", self
self.total_score += self.DEATH_PENALTY
if self.total_score <= self.GIVEUP_THRESHOLD:
# game is over...
#print "giveup:", self
self.state = 0
else:
# try again...
self.state = 1
self.partial_score = 0
self.ch = ""
return
def flush(self):
self.total_score += self.partial_score * self.partial_score
self.partial_score = 0.0
return
def accept(self, s):
try:
c = unicode(s, self.encoding)
except UnicodeError:
c = ""
for (score, pat, flags) in self.CHARSET:
if pat.match(c):
if self.chunk_type == 0 or not (self.chunk_type & flags):
self.flush()
self.chunk_type = flags
self.partial_score += score
break
else:
self.flush()
self.chunk_type = 0
self.partial_score += self.SCORE_DEFAULT
return
def finish(self):
self.flush()
if 1 < self.state:
self.die()
return
## CHARACTER SETS
## ISO-8859-*
##
class ISO8859_Recognizer(EncodingRecognizer):
def __init__(self):
return EncodingRecognizer.__init__(self, "iso8859_1")
def feed(self, c):
if self.state == 0: # already dead?
return
elif self.state == 1: # ascii or iso?
if c < 0x7f or (0xa0 <= c and c <= 0xff):
self.state = 1
self.accept(chr(c))
else:
self.die()
return
## EUC-JP
##
class EUCJP_Recognizer(EncodingRecognizer):
def __init__(self):
self.hankaku = False
return EncodingRecognizer.__init__(self, "japanese.euc_jp")
def feed(self, c):
if self.state == 0: # already dead?
return
# 1stbyte
elif self.state == 1:
if c < 0x7f: # ascii?
# succeed
self.state = 1
self.accept(chr(c))
self.ch = ""
# IGNORE EUC-JP hankaku chars, no one is using
# elif 0x8e == c: # hankaku-kana 1stbyte?
# # next
# self.state = 2
# self.ch = chr(c)
# self.hankaku = True
elif 0xa1 <= c and c <= 0xfe: # kanji 1stbyte?
# next
self.state = 2
self.ch = chr(c)
self.hankaku = False
else:
self.die()
# 2ndbyte
elif self.state == 2:
if self.hankaku and (0xa1 <= c and c <= 0xdf): # hankaku-kana 2ndbyte?
# succeed
self.ch += chr(c)
self.accept(self.ch)
self.state = 1
self.ch = ""
elif not self.hankaku and (0xa1 <= c and c <= 0xfe): # kanji 2ndbyte?
# succeed
self.ch += chr(c)
self.accept(self.ch)
self.state = 1
self.ch = ""
else:
self.die()
return
## CP932
##
class CP932_Recognizer(EncodingRecognizer):
def __init__(self):
return EncodingRecognizer.__init__(self, "japanese.ms932")
def feed(self, c):
if self.state == 0: # already dead?
return
# 1stbyte
elif self.state == 1:
if c < 0x7f: # ascii?
# succeed
self.state = 1
self.accept(chr(c))
self.ch = ""
elif 0xa1 <= c and c <= 0xdf: # hankaku-kana?
# succeed
self.state = 1
self.accept(chr(c))
self.ch = ""
elif (0x81 <= c and c <= 0x9f) or (0xe0 <= c and c <= 0xee) \
or (0xfa <= c and c <= 0xfc): # kanji 1stbyte?
# next
self.state = 2
self.ch = chr(c)
else:
self.die()
# 2ndbyte
elif self.state == 2:
if 0x40 <= c and c <= 0xfc and c != 0x7f: # kanji 2ndbyte?
# succeed
self.accept(self.ch+chr(c))
self.state = 1
self.ch = ""
else:
self.die()
return
## UTF-8
##
class UTF8_Recognizer(EncodingRecognizer):
def __init__(self):
self.left = 0
return EncodingRecognizer.__init__(self, "utf8")
def feed(self, c):
if self.state == 0: # already dead?
return
# 1stbyte
elif self.state == 1:
if c <= 0x7f: # 00xxxxxx: 1byte only?
# succeed
self.state = 1
self.accept(chr(c))
self.ch = ""
elif c & 0xe0 == 0xc0: # 110xxxxx: 2bytes
# next
self.state = 2
self.left = 1
self.ch = chr(c)
elif c & 0xf0 == 0xe0: # 1110xxxx: 3bytes
# next
self.state = 2
self.left = 2
self.ch = chr(c)
elif c & 0xf8 == 0xf0: # 11110xxx: 4bytes
# next
self.state = 2
self.left = 3
self.ch = chr(c)
elif c & 0xfc == 0xf8: # 111110xx: 5bytes
# next
self.state = 2
self.left = 4
self.ch = chr(c)
else:
self.die()
# n-th byte (where 2<=n)
else:
if c & 0xc0 == 0x80: # 10xxxxxx: continuous?
self.state += 1
self.left -= 1
self.ch += chr(c)
if self.left == 0: # finished?
# succeed
self.state = 1
self.accept(self.ch)
self.ch = ""
else:
# next
pass
else:
self.die()
return
# guess
def guess(s):
recognizer = [
EUCJP_Recognizer(),
CP932_Recognizer(),
ISO8859_Recognizer(),
UTF8_Recognizer()
]
for c in s:
for r in recognizer:
r.feed(ord(c))
for r in recognizer:
r.finish()
#print r
recognizer.sort(lambda a,b: cmp(b.total_score, a.total_score))
return recognizer[0].encoding
# test suite
def test(s0, test_encodings):
false_encodings = [ "japanese.euc_jp", "japanese.ms932", "utf8", "iso8859_1" ]
for enc1 in test_encodings:
try:
s = s0.encode(enc1)
except UnicodeError:
continue
print "try '%s' in %s (%s)" % (s0, enc1, " ".join(map(lambda c:"%02x" % ord(c), s)))
for enc2 in false_encodings:
if enc1 != enc2:
try:
x = str(unicode(s, enc2))
print " (could be: '%s' in %s)" % (x, enc2)
except UnicodeError:
continue
genc = guess(s)
if genc == enc1:
print " CORRECT:", genc
else:
print " ! INCORRECT:", genc
print
return
def test_suite():
# kana only
test(u"こんにちは", ["japanese.euc_jp", "japanese.ms932", "utf8"])
# kana + alphanum
test(u"AはBとCである", ["japanese.euc_jp", "japanese.ms932", "utf8"])
# kana + kanji
test(u"毎朝新聞ニュース", ["japanese.euc_jp", "japanese.ms932", "utf8"])
# kanji + hankakukana
test(u"無題ﾄﾞｷｭﾒﾝﾄ", ["japanese.ms932", "utf8"])
# iso8859-1
test(u"Enzyklop\u00e4die", ["utf8", "iso8859_1"])
return
# main
test_suite(); sys.exit(0)
if __name__ == "__main__":
import fileinput
for s in fileinput.input():
print guess(s)</protect>

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