X-Git-Url: http://git.veekun.com/zzz-pokedex.git/blobdiff_plain/a846073cb5288638fa103eade44098fa86d679d8..16c4ccddba0048458cafc3c38032e121e5081ebd:/pokedex/lookup.py?ds=inline diff --git a/pokedex/lookup.py b/pokedex/lookup.py index 90fb3d3..1363c7a 100644 --- a/pokedex/lookup.py +++ b/pokedex/lookup.py @@ -1,31 +1,441 @@ # encoding: utf8 +from collections import namedtuple +import os, os.path +import pkg_resources +import random +import re +import shutil +import unicodedata + from sqlalchemy.sql import func +import whoosh +import whoosh.filedb.filestore +import whoosh.filedb.fileindex +import whoosh.index +from whoosh.qparser import QueryParser +import whoosh.scoring +import whoosh.spelling +from pokedex.db import connect import pokedex.db.tables as tables +from pokedex.roomaji import romanize + +__all__ = ['PokedexLookup'] -def lookup(session, name): - """Attempts to find some sort of object, given a database session and name. - Returns a list of (object, matchiness) tuples. Matchiness is 1 for exact - matches. It is possible to get multiple exact matches; for example, - 'Metronome' will match both the move and the item. In these cases, the - results are returned in rough order of "importance", e.g., Pokémon come - before moves come before types. +rx_is_number = re.compile('^\d+$') - This function does fuzzy matching iff there are no exact matches. +LookupResult = namedtuple('LookupResult', + ['object', 'name', 'language', 'iso3166', 'exact']) - Formes are not returned; "Shaymin" will return only grass Shaymin. - - Currently recognizes: - - Pokémon names: "Eevee" +class LanguageWeighting(whoosh.scoring.Weighting): + """A scoring class that forces otherwise-equal English results to come + before foreign results. """ - q = session.query(tables.Pokemon) \ - .filter(func.lower(tables.Pokemon.name) == name.lower()) \ - .filter_by(forme_base_pokemon_id=None) + def score(self, searcher, fieldnum, text, docnum, weight, QTF=1): + doc = searcher.stored_fields(docnum) + if doc['language'] == None: + # English (well, "default"); leave it at 1 + return weight + elif doc['language'] == u'Roomaji': + # Give Roomaji a little boost; it's most likely to be searched + return weight * 0.95 + else: + # Everything else can drop down the totem pole + return weight * 0.9 + + +class PokedexLookup(object): + INTERMEDIATE_LOOKUP_RESULTS = 25 + MAX_LOOKUP_RESULTS = 10 + + # Dictionary of table name => table class. + # Need the table name so we can get the class from the table name after we + # retrieve something from the index + indexed_tables = dict( + (cls.__tablename__, cls) + for cls in ( + tables.Ability, + tables.Item, + tables.Move, + tables.Pokemon, + tables.Type, + ) + ) + + + def __init__(self, directory=None, session=None, recreate=False): + """Opens the whoosh index stored in the named directory. If the index + doesn't already exist, it will be created. + + `directory` + Directory containing the index. Defaults to a location within the + `pokedex` egg directory. + + `session` + If the index needs to be created, this database session will be + used. Defaults to an attempt to connect to the default SQLite + database installed by `pokedex setup`. + + `recreate` + If set to True, the whoosh index will be created even if it already + exists. + """ + + # By the time this returns, self.index, self.speller, and self.session + # must be set + + # Defaults + if not directory: + directory = pkg_resources.resource_filename('pokedex', + 'data/whoosh-index') + + if session: + self.session = session + else: + self.session = connect() + + # Attempt to open or create the index + directory_exists = os.path.exists(directory) + if directory_exists and not recreate: + # Already exists; should be an index! Bam, done. + try: + self.index = whoosh.index.open_dir(directory, indexname='MAIN') + spell_store = whoosh.filedb.filestore.FileStorage(directory) + self.speller = whoosh.spelling.SpellChecker(spell_store) + return + except whoosh.index.EmptyIndexError as e: + # Apparently not a real index. Fall out and create it + pass + + # Delete and start over if we're going to bail anyway. + if directory_exists and recreate: + # Be safe and only delete if it looks like a whoosh index, i.e., + # everything starts with _ + if all(f[0] == '_' for f in os.listdir(directory)): + shutil.rmtree(directory) + directory_exists = False + + if not directory_exists: + os.mkdir(directory) + + + ### Create index + schema = whoosh.fields.Schema( + name=whoosh.fields.ID(stored=True), + table=whoosh.fields.ID(stored=True), + row_id=whoosh.fields.ID(stored=True), + language=whoosh.fields.STORED, + iso3166=whoosh.fields.STORED, + display_name=whoosh.fields.STORED, # non-lowercased name + forme_name=whoosh.fields.ID, + ) + + self.index = whoosh.index.create_in(directory, schema=schema, + indexname='MAIN') + writer = self.index.writer() + + # Index every name in all our tables of interest + # speller_entries becomes a list of (word, score) tuples; the score is + # 2 for English names, 1.5 for Roomaji, and 1 for everything else. I + # think this biases the results in the direction most people expect, + # especially when e.g. German names are very similar to English names + speller_entries = [] + for cls in self.indexed_tables.values(): + q = session.query(cls) + + for row in q.yield_per(5): + # Need to give forme_name a dummy value because I can't + # search for explicitly empty fields. Boo. + row_key = dict(table=unicode(cls.__tablename__), + row_id=unicode(row.id), + forme_name=u'__empty__') + + def add(name, language, iso3166, score): + normalized_name = self.normalize_name(name) + writer.add_document( + name=normalized_name, display_name=name, + language=language, iso3166=iso3166, + **row_key + ) + speller_entries.append((normalized_name, score)) + + # If this is a form, mark it as such + if getattr(row, 'forme_base_pokemon_id', None): + row_key['forme_name'] = row.forme_name + + name = row.name + add(name, None, u'us', 1) + + # Pokemon also get other languages + for foreign_name in getattr(row, 'foreign_names', []): + moonspeak = foreign_name.name + if name == moonspeak: + # Don't add the English name again as a different + # language; no point and it makes spell results + # confusing + continue + + add(moonspeak, foreign_name.language.name, + foreign_name.language.iso3166, + 3) + + # Add Roomaji too + if foreign_name.language.name == 'Japanese': + roomaji = romanize(foreign_name.name) + add(roomaji, u'Roomaji', u'jp', 8) + + writer.commit() + + # Construct and populate a spell-checker index. Quicker to do it all + # at once, as every call to add_* does a commit(), and those seem to be + # expensive + self.speller = whoosh.spelling.SpellChecker(self.index.storage) + self.speller.add_scored_words(speller_entries) + + + def normalize_name(self, name): + """Strips irrelevant formatting junk from name input. + + Specifically: everything is lowercased, and accents are removed. + """ + # http://stackoverflow.com/questions/517923/what-is-the-best-way-to-remove-accents-in-a-python-unicode-string + # Makes sense to me. Decompose by Unicode rules, then remove combining + # characters, then recombine. I'm explicitly doing it this way instead + # of testing combining() because Korean characters apparently + # decompose! But the results are considered letters, not combining + # characters, so testing for Mn works well, and combining them again + # makes them look right. + nkfd_form = unicodedata.normalize('NFKD', unicode(name)) + name = u"".join(c for c in nkfd_form + if unicodedata.category(c) != 'Mn') + name = unicodedata.normalize('NFC', name) + + name = name.strip() + name = name.lower() + + return name + + + def _parse_table_name(self, name): + """Takes a singular table name, table name, or table object and returns + the table name. + + Returns None for a bogus name. + """ + if hasattr(name, '__tablename__'): + return getattr(name, '__tablename__') + elif name in self.indexed_tables: + return name + elif name + 's' in self.indexed_tables: + return name + 's' + else: + # Bogus. Be nice and return dummy + return None + + def _whoosh_records_to_results(self, records, exact=True): + """Converts a list of whoosh's indexed records to LookupResult tuples + containing database objects. + """ + # XXX this 'exact' thing is getting kinda leaky. would like a better + # way to handle it, since only lookup() cares about fuzzy results + seen = {} + results = [] + for record in records: + # Skip dupes + seen_key = record['table'], record['row_id'] + if seen_key in seen: + continue + seen[seen_key] = True + + cls = self.indexed_tables[record['table']] + obj = self.session.query(cls).get(record['row_id']) + + results.append(LookupResult(object=obj, + name=record['display_name'], + language=record['language'], + iso3166=record['iso3166'], + exact=exact)) + + return results + + + def lookup(self, input, valid_types=[], exact_only=False): + """Attempts to find some sort of object, given a name. + + Returns a list of named (object, name, language, iso3166, exact) + tuples. `object` is a database object, `name` is the name under which + the object was found, `language` and `iso3166` are the name and country + code of the language in which the name was found, and `exact` is True + iff this was an + exact match. + + This function currently ONLY does fuzzy matching if there are no exact + matches. + + Formes are not returned unless requested; "Shaymin" will return only + grass Shaymin. + + Extraneous whitespace is removed with extreme prejudice. + + Recognizes: + - Names: "Eevee", "Surf", "Run Away", "Payapa Berry", etc. + - Foreign names: "Iibui", "Eivui" + - Fuzzy names in whatever language: "Evee", "Ibui" + - IDs: "133", "192", "250" + Also: + - Type restrictions. "type:psychic" will only return the type. This + is how to make ID lookup useful. Multiple type specs can be entered + with commas, as "move,item:1". If `valid_types` are provided, any + type prefix will be ignored. + - Alternate formes can be specified merely like "wash rotom". + + `input` + Name of the thing to look for. + + `valid_types` + A list of table objects or names, e.g., `['pokemon', 'moves']`. If + this is provided, only results in one of the given tables will be + returned. + + `exact_only` + If True, only exact matches are returned. If set to False (the + default), and the provided `name` doesn't match anything exactly, + spelling correction will be attempted. + """ + + name = self.normalize_name(input) + exact = True + form = None + + # Remove any type prefix (pokemon:133) before constructing a query + if ':' in name: + prefix_chunk, name = name.split(':', 1) + name = name.strip() + + if not valid_types: + # Only use types from the query string if none were explicitly + # provided + prefixes = prefix_chunk.split(',') + valid_types = [_.strip() for _ in prefixes] + + # Random lookup + if name == 'random': + return self.random_lookup(valid_types=valid_types) + + # Do different things depending what the query looks like + # Note: Term objects do an exact match, so we don't have to worry about + # a query parser tripping on weird characters in the input + if '*' in name or '?' in name: + exact_only = True + query = whoosh.query.Wildcard(u'name', name) + elif rx_is_number.match(name): + # Don't spell-check numbers! + exact_only = True + query = whoosh.query.Term(u'row_id', name) + else: + # Not an integer + query = whoosh.query.Term(u'name', name) \ + & whoosh.query.Term(u'forme_name', u'__empty__') + + # If there's a space in the input, this might be a form + if ' ' in name: + form, formless_name = name.split(' ', 1) + form_query = whoosh.query.Term(u'name', formless_name) \ + & whoosh.query.Term(u'forme_name', form) + query = query | form_query + + ### Filter by type of object + type_terms = [] + for valid_type in valid_types: + table_name = self._parse_table_name(valid_type) + if table_name: + # Quietly ignore bogus valid_types; more likely to DTRT + type_terms.append(whoosh.query.Term(u'table', table_name)) + + if type_terms: + query = query & whoosh.query.Or(type_terms) + + + ### Actual searching + searcher = self.index.searcher() + # XXX is this kosher? docs say search() takes a weighting arg, but it + # certainly does not + searcher.weighting = LanguageWeighting() + results = searcher.search(query, + limit=self.INTERMEDIATE_LOOKUP_RESULTS) + + # Look for some fuzzy matches if necessary + if not exact_only and not results: + exact = False + results = [] + + for suggestion in self.speller.suggest( + name, self.INTERMEDIATE_LOOKUP_RESULTS): + + query = whoosh.query.Term('name', suggestion) + results.extend(searcher.search(query)) + + ### Convert results to db objects + objects = self._whoosh_records_to_results(results, exact=exact) + + # Only return up to 10 matches; beyond that, something is wrong. We + # strip out duplicate entries above, so it's remotely possible that we + # should have more than 10 here and lost a few. The speller returns 25 + # to give us some padding, and should avoid that problem. Not a big + # deal if we lose the 25th-most-likely match anyway. + return objects[:self.MAX_LOOKUP_RESULTS] + + + def random_lookup(self, valid_types=[]): + """Returns a random lookup result from one of the provided + `valid_types`. + """ + + tables = [] + for valid_type in valid_types: + table_name = self._parse_table_name(valid_type) + if table_name: + tables.append(self.indexed_tables[table_name]) + + if not tables: + # n.b.: It's possible we got a list of valid_types and none of them + # were valid, but this function is guaranteed to return + # *something*, so it politely selects from the entire index isntead + tables = self.indexed_tables.values() + + # Rather than create an array of many hundred items and pick randomly + # from it, just pick a number up to the total number of potential + # items, then pick randomly from that, and partition the whole range + # into chunks. This also avoids the slight problem that the index + # contains more rows (for languages) for some items than others. + # XXX ought to cache this (in the index?) if possible + total = 0 + partitions = [] + for table in tables: + count = self.session.query(table).count() + total += count + partitions.append((table, count)) + + n = random.randint(1, total) + while n > partitions[0][1]: + n -= partitions[0][1] + partitions.pop(0) + + return self.lookup(unicode(n), valid_types=[ partitions[0][0] ]) + + def prefix_lookup(self, prefix): + """Returns terms starting with the given exact prefix. + + No special magic is currently done with the name; type prefixes are not + recognized. + """ + + query = whoosh.query.Prefix(u'name', self.normalize_name(prefix)) + + searcher = self.index.searcher() + searcher.weighting = LanguageWeighting() + results = searcher.search(query) # XXX , limit=self.MAX_LOOKUP_RESULTS) - try: - result = q.one() - return [ (result, 1) ] - except: - return [] + return self._whoosh_records_to_results(results)