Python 不能被拼写纠正。否则，nummbers auoaaixao carrmichal将导致numbers和carmichael之间的结果为空，您将无法确定哪个输入映射到哪个输出。包含了原始的未更正项后，现在可以轻松地将这些项映射到更正项，而不使用不可更正项。@

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不能被拼写纠正。否则，

nummbers auoaaixao carrmichal

将导致

numbers

和

carmichael

之间的结果为空，您将无法确定哪个输入映射到哪个输出。包含了原始的未更正项后，现在可以轻松地将这些项映射到更正项，而不使用不可更正项。@Basj：我使用1000个随机生成的“单词”对此处生成的数据库进行了测试，并且使用基于

联合的查询的函数在每次测试（100次重复）的2.6毫秒内执行，而每个术语循环并执行单独查询的函数在2.9毫秒内执行（重复次数相同）。这是一个有限的测试，这里生成的有限的
spellfix1
表只为这100个随机项生成了一个结果，但它很好地说明了为什么要在这里使用
UNION
。
import sqlite3
db = sqlite3.connect(':memory:')
c = db.cursor()
c.execute('CREATE TABLE mytable (id integer, description text)')
c.execute('INSERT INTO mytable VALUES (1, "Riemann")')
c.execute('INSERT INTO mytable VALUES (2, "All the Carmichael numbers")')

db.enable_load_extension(True)
db.load_extension('./spellfix')
c.execute('SELECT * FROM mytable WHERE editdist3(description, "Riehmand") < 300'); print c.fetchall()

#Query: 'Riehmand'
#Answer: [(1, u'Riemann')]

c.execute('CREATE VIRTUAL TABLE mytable3 USING spellfix1')
c.execute('INSERT INTO mytable3(word) VALUES ("Riemann")')
c.execute('SELECT * FROM mytable3 WHERE word MATCH "Riehmand"'); print c.fetchall()

#Query: 'Riehmand'
#Answer: [(u'Riemann', 1, 76, 0, 107, 7)], working!

c.execute('CREATE VIRTUAL TABLE mytable2 USING fts4(id integer, description text)')
c.execute('INSERT INTO mytable2 VALUES (2, "All the Carmichael numbers")')
c.execute('SELECT * FROM mytable2 WHERE description MATCH "NUMBERS carmichael"'); print c.fetchall()

#Query: 'NUMBERS carmichael'
#Answer: [(2, u'All the Carmichael numbers')]

INSERT INTO demo(word) SELECT term FROM search_aux WHERE col='*';

CREATE VIRTUAL TABLE mytable2_terms USING fts4aux(mytable2);
INSERT INTO mytable3(word) SELECT term FROM mytable2_terms WHERE col='*';

INSERT INTO mytable3(word)
    SELECT term FROM mytable2_terms
    WHERE col='*' AND 
        term not in (SELECT word from mytable3_vocab);

def spellcheck_terms(conn, terms):
    cursor = conn.cursor()
    base_spellfix = """
        SELECT :term{0} as term, word FROM spellfix1data
        WHERE word MATCH :term{0} and top=1
    """
    terms = terms.split()
    params = {"term{}".format(i): t for i, t in enumerate(terms, 1)}
    query = " UNION ".join([
        base_spellfix.format(i + 1) for i in range(len(params))])
    cursor.execute(query, params)
    correction_map = dict(cursor)
    return " ".join([correction_map.get(t, t) for t in terms])

def spellchecked_search(conn, terms):
    corrected_terms = spellcheck_terms(conn, terms)
    cursor = conn.cursor()
    fts_query = 'SELECT * FROM mytable2 WHERE mytable2 MATCH ?'
    cursor.execute(fts_query, (corrected_terms,))
    return cursor.fetchall()

import re
import sqlite3
import sys

class FTS4SpellfixSearch(object):
    def __init__(self, conn, spellfix1_path):
        self.conn = conn
        self.conn.enable_load_extension(True)
        self.conn.load_extension(spellfix1_path)

    def create_schema(self):
        self.conn.executescript(
            """
            CREATE VIRTUAL TABLE IF NOT EXISTS fts4data
                USING fts4(description text);
            CREATE VIRTUAL TABLE IF NOT EXISTS fts4data_terms
                USING fts4aux(fts4data);
            CREATE VIRTUAL TABLE IF NOT EXISTS spellfix1data
                USING spellfix1;
            """
        )

    def index_text(self, *text):
        cursor = self.conn.cursor()
        with self.conn:
            params = ((t,) for t in text)
            cursor.executemany("INSERT INTO fts4data VALUES (?)", params)
            cursor.execute(
                """
                INSERT INTO spellfix1data(word)
                SELECT term FROM fts4data_terms
                WHERE col='*' AND
                    term not in (SELECT word from spellfix1data_vocab)
                """
            )

    # fts3 / 4 search expression tokenizer
    # no attempt is made to validate the expression, only
    # to identify valid search terms and extract them.
    # the fts3/4 tokenizer considers any alphanumeric ASCII character
    # and character in the range U+0080 and over to be terms.
    if sys.maxunicode == 0xFFFF:
        # UCS2 build, keep it simple, match any UTF-16 codepoint 0080 and over
        _fts4_expr_terms = re.compile(u"[a-zA-Z0-9\u0080-\uffff]+")
    else:
        # UCS4
        _fts4_expr_terms = re.compile(u"[a-zA-Z0-9\u0080-\U0010FFFF]+")

    def _terms_from_query(self, search_query):
        """Extract search terms from a fts3/4 query

        Returns a list of terms and a template such that
        template.format(*terms) reconstructs the original query.

        terms using partial* syntax are ignored, as you can't distinguish
        between a misspelled prefix search that happens to match existing
        tokens and a valid spelling that happens to have 'near' tokens in
        the spellfix1 database that would not otherwise be matched by fts4

        """
        template, terms, lastpos = [], [], 0
        for match in self._fts4_expr_terms.finditer(search_query):
            token, (start, end) = match.group(), match.span()
            # skip columnname: and partial* terms by checking next character
            ismeta = search_query[end:end + 1] in {":", "*"}
            # skip digits if preceded by "NEAR/"
            ismeta = ismeta or (
                token.isdigit() and template and template[-1] == "NEAR"
                and "/" in search_query[lastpos:start])
            if token not in {"AND", "OR", "NOT", "NEAR"} and not ismeta:
                # full search term, not a keyword, column name or partial*
                terms.append(token)
                token = "{}"
            template += search_query[lastpos:start], token
            lastpos = end
        template.append(search_query[lastpos:])
        return terms, "".join(template)

    def spellcheck_terms(self, search_query):
        cursor = self.conn.cursor()
        base_spellfix = """
            SELECT :term{0} as term, word FROM spellfix1data
            WHERE word MATCH :term{0} and top=1
        """
        terms, template = self._terms_from_query(search_query)
        params = {"term{}".format(i): t for i, t in enumerate(terms, 1)}
        query = " UNION ".join(
            [base_spellfix.format(i + 1) for i in range(len(params))]
        )
        cursor.execute(query, params)
        correction_map = dict(cursor)
        return template.format(*(correction_map.get(t, t) for t in terms))

    def search(self, search_query):
        corrected_query = self.spellcheck_terms(search_query)
        cursor = self.conn.cursor()
        fts_query = "SELECT * FROM fts4data WHERE fts4data MATCH ?"
        cursor.execute(fts_query, (corrected_query,))
        return {
            "terms": search_query,
            "corrected": corrected_query,
            "results": cursor.fetchall(),
        }

>>> db = sqlite3.connect(":memory:")
>>> fts = FTS4SpellfixSearch(db, './spellfix')
>>> fts.create_schema()
>>> fts.index_text("All the Carmichael numbers")  # your example
>>> from pprint import pprint
>>> pprint(fts.search('NUMMBER carmickaeel'))
{'corrected': 'numbers carmichael',
 'results': [('All the Carmichael numbers',)],
 'terms': 'NUMMBER carmickaeel'}
>>> fts.index_text(
...     "They are great",
...     "Here some other numbers",
... )
>>> pprint(fts.search('here some'))  # edgecase, multiple spellfix matches
{'corrected': 'here some',
 'results': [('Here some other numbers',)],
 'terms': 'here some'}
>>> pprint(fts.search('NUMMBER NOT carmickaeel'))  # using fts4 query syntax 
{'corrected': 'numbers NOT carmichael',
 'results': [('Here some other numbers',)],
 'terms': 'NUMMBER NOT carmickaeel'}

import sqlite3
db = sqlite3.connect(':memory:')
db.enable_load_extension(True)
db.load_extension('./spellfix')
c = db.cursor()
c.execute("CREATE VIRTUAL TABLE mytable2 USING fts4(description text)")
c.execute("CREATE VIRTUAL TABLE mytable2_terms USING fts4aux(mytable2)")
c.execute("CREATE VIRTUAL TABLE mytable3 USING spellfix1")
c.execute("INSERT INTO mytable2 VALUES ('All the Carmichael numbers')")   # populate the table
c.execute("INSERT INTO mytable2 VALUES ('They are great')")
c.execute("INSERT INTO mytable2 VALUES ('Here some other numbers')")
c.execute("INSERT INTO mytable3(word) SELECT term FROM mytable2_terms WHERE col='*'")

def search(query):
    # Correcting each query term with spellfix table
    correctedquery = []
    for t in query.split():
        spellfix_query = "SELECT word FROM mytable3 WHERE word MATCH ? and top=1"
        c.execute(spellfix_query, (t,))
        r = c.fetchone()
        correctedquery.append(r[0] if r is not None else t)  # correct the word if any match in the spellfix table; if no match, keep the word spelled as it is (then the search will give no result!)

    correctedquery = ' '.join(correctedquery)

    # Now do the FTS
    fts_query = 'SELECT * FROM mytable2 WHERE description MATCH ?'
    c.execute(fts_query, (correctedquery,))
    return {'result': c.fetchall(), 'correctedquery': correctedquery, 'query': query}

print(search('NUMBBERS carmickaeel'))
print(search('some HERE'))
print(search('some qsdhiuhsd'))