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97 lines
3.8 KiB
Python
Executable File
97 lines
3.8 KiB
Python
Executable File
# This module is part of the Pyndex project and is Copyright 2003 Amir
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# Bakhtiar (amir@divmod.org). This is free software; you can redistribute
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# it and/or modify it under the terms of version 2.1 of the GNU Lesser
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# General Public License as published by the Free Software Foundation.
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import string
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class Splitter(object):
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"""Split plain text into words" utility class
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Adapted from David Mertz's article in IBM developerWorks
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Needs work to handle international characters, etc"""
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## __slots__ = ['stemmer', 'porter', 'stopwording', 'word_only', 'nonword',
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## 'nondigits', 'alpha', 'ident', 'tokens', 'position']
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stopWords = {'and': 1, 'be': 1, 'to': 1, 'that': 1, 'into': 1,
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'it': 1, 'but': 1, 'as': 1, 'are': 1, 'they': 1,
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'in': 1, 'not': 1, 'such': 1, 'with': 1, 'by': 1,
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'is': 1, 'if': 1, 'a': 1, 'on': 1, 'for': 1,
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'no': 1, 'these': 1, 'of': 1, 'there': 1,
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'this': 1, 'will': 1, 'their': 1, 's': 1, 't': 1,
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'then': 1, 'the': 1, 'was': 1, 'or': 1, 'at': 1}
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yes = string.lowercase + string.digits + '' # throw in any extras
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nonword = ''
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for i in range(0,255):
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if chr(i) not in yes:
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nonword += chr(i)
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word_only = string.maketrans(nonword, " " * len(nonword))
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nondigits = string.join(map(chr, range(0,48)) + map(chr, range(58,255)), '')
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alpha = string.join(map(chr, range(65,91)) + map(chr, range(97,123)), '')
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ident = string.join(map(chr, range(256)), '')
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def close(self):
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# Lupy support
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pass
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def tokenStream(self, fieldName, file, casesensitive=False):
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"""Split text/plain string into a list of words
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"""
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self.tokens = self.split(file.read())
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self.position = 0
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return self
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def next(self):
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if self.position >= len(self.tokens):
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return None
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res = Token(self.tokens[self.position])
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self.position += 1
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return res
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def split(self, text, casesensitive=0):
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# Speedup trick: attributes into local scope
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word_only = self.word_only
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ident = self.ident
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alpha = self.alpha
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nondigits = self.nondigits
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# Let's adjust case if not case-sensitive
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if not casesensitive: text = string.lower(text)
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# Split the raw text
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allwords = text.translate(word_only).split() # Let's strip funny byte values
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# Finally, let's skip some words not worth indexing
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words = []
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for word in allwords:
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if len(word) > 32: continue # too long (probably gibberish)
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# Identify common patterns in non-word data (binary, UU/MIME, etc)
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num_nonalpha = len(word.translate(ident, alpha))
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numdigits = len(word.translate(ident, nondigits))
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if numdigits > len(word)-2: # almost all digits
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if numdigits > 5: # too many digits is gibberish
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continue # a moderate number is year/zipcode/etc
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elif num_nonalpha*2 > len(word): # too much scattered nonalpha = gibberish
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continue
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word = word.translate(word_only) # Let's strip funny byte values
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subwords = word.split() # maybe embedded non-alphanumeric
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for subword in subwords: # ...so we might have subwords
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if len(subword) <= 1: continue # too short a subword
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words.append(subword)
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return words
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class Token:
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def __init__(self, trmText):
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self.trmText = trmText
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def termText(self):
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return self.trmText
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