Source code for tagit.external.spellcheck

"""Spellcheck

From:
    http://norvig.com/spell-correct.html

Part of the tagit module.
A copy of the license is provided with the project.
Author: Matthias Baumgartner, 2016

"""
# IMPORTS
import re, collections
from os.path import join, dirname

# EXPORTS
__all__ = ('correct', )

## CODE ##

[docs]class Spellcheck(object): def __init__(self, lang='en'): if lang == 'de': path = join(dirname(__file__), '..', 'resources', 'dict', 'dict_de.t') else: # Default en path = join(dirname(__file__), '..', 'resources', 'dict', 'dict_en.t') self.NWORDS = self.train(self.words(file(path).read())) self.alphabet = 'abcdefghijklmnopqrstuvwxyz' def words(self, text): return re.findall('[a-z]+', text.lower()) def train(self, features): model = collections.defaultdict(lambda: 1) for f in features: model[f] += 1 return model def edits1(self, word): splits = [(word[:i], word[i:]) for i in range(len(word) + 1)] deletes = [a + b[1:] for a, b in splits if b] transposes = [a + b[1] + b[0] + b[2:] for a, b in splits if len(b)>1] replaces = [a + c + b[1:] for a, b in splits for c in self.alphabet if b] inserts = [a + c + b for a, b in splits for c in self.alphabet] return set(deletes + transposes + replaces + inserts) def known_edits2(self, word): return set(e2 for e1 in self.edits1(word) for e2 in self.edits1(e1) if e2 in self.NWORDS) def known(self, words): return set(w for w in words if w in self.NWORDS) def correct(self, word): candidates = self.known([word]) or self.known(self.edits1(word)) or self.known_edits2(word) or [word] return max(candidates, key=self.NWORDS.get) ## EOF ##