django16--全文搜索
1，全文搜索引擎
Django提供haystack来支持全文搜索。
需要的依赖：
haystack
whoosh
jieba
使用流程：
1)下载依赖
2)配置haystack应用
3)配置搜索引擎
4)设置搜索结果的分页
HAYSTACK_SEARCH_RESULTS_PER_PAGE = 10
5)索引的设置
HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
6)创建索引类
需要创建一个专门的应用来放这个类，而且这个索引类所在的文件名必须是search_indexes.py
7）设置数据模板
目录和文件位置以及名字按规定来。
在文件里面，指定针对的内容
8）配置检索路由在根模块的urls
子路由不需要自己配了，因为下载的应用已经自己配好，查看的目录
C:\Users\admin\AppData\Local\Programs\Python\Python36-32\Lib\site-packages\haystack
9）创建结果展示页面，路径和名称固定
10）设定中文分词
11)生成索引
12)在需要的页面上提供搜索表单
1.下载：（django-haystack，Whoosh，jieba）
2.在settings.py中内容：
（1）添加应用：INSTALLED_APPS = [ 'haystack', ]
（2）配置搜索引擎配置：
HAYSTACK_CONNECTIONS = {
'default': {
'ENGINE': 'mysearch.whoosh_cn_backend.WhooshEngine',
# 将来需要修改
'PATH': os.path.join(BASE_DIR, 'whoosh_index'),
}
}
（3）设置分页，每页显示的条数
HAYSTACK_SEARCH_RESULTS_PER_PAGE = 2
（4） 索引配置
HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
# 1.子模块应用加入 INSTALLED_APPS = [ # 全文搜索 'haystack', 'mysearch', ] # 2.配置搜索引擎配置 HAYSTACK_CONNECTIONS = { 'default': { 'ENGINE': 'mysearch.whoosh_cn_backend.WhooshEngine', # 将来需要修改 'PATH': os.path.join(BASE_DIR, 'whoosh_index'), } } # 3.设置分页，每页显示的条数 HAYSTACK_SEARCH_RESULTS_PER_PAGE = 2 # 4.索引配置 HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
3. 创建索引类：（1）创建一个应用：python manage.py startapp mysearch
（2）然后把应用添加到settings.py中 ：INSTALLED_APPS = [ 'haystack', ' mysearch' ]
（3）在mysearch子模块中创建：search_indexes.py文件，
（4）文件里面写内容如下：
# 替换模块导入位置 from myblog.models import Article from haystack import indexes class ArticleIndex(indexes.SearchIndex, indexes.Indexable): text = indexes.CharField(document=True, use_template=True) def get_model(self): return Article def index_queryset(self, using=None): return self.get_model().objects.all()4.设置数据模板：目录和文件位置以及名字按规定来。在文件里面，指定针对的内容
（1）在项目目录下创建temp，然后依次创建py1811/mypro/temp/search/indexes/myblog/article_text.txt
myblog为子模块名字
（2）在article_text.txt中写入按照什么可以搜索到：{ { object.title }} { { object.content }}
{ { object.title }} { { object.content }}5.配置检索路由在根模块的urls ：
urlpatterns = [
# 配置检索的路由
url(r'^search/', include("haystack.urls")),
]
注意：子路由不需要自己配了，因为下载的应用已经自己配好，查看的目录
C:\Users\admin\AppData\Local\Programs\Python\Python36-32\Lib\site-packages\haystack\urls.pyurlpatterns = [ url(r'^admin/', admin.site.urls), # 子模块 url(r'^myblog/', include('myblog.urls')), # 静态资源 url(r'^index1/$', views.index1), # 主页面的路由 url(r'^base/$', views.base), # 继承主页面的子页面路由 url(r'^base_index1/$', views.base_index1), # 配置检索的路由 url(r'^search/', include("haystack.urls")), ]6.创建结果展示页面，路径和名称固定，
在temp/search/创建search.html，内容如下：
{% if query %} 搜索结果如下：
{% for result in page.object_list %} { { result.object.title }}
{% empty %}啥也没找到
{% endfor %} {% if page.has_previous or page.has_next %}{% if page.has_previous %} {% endif %} « 上一页 {% if page.has_previous %} {% endif %} | {% if page.has_next %} {% endif %} 下一页 » {% if page.has_next %} {% endif %}{% endif %} {% endif %}7.设定中文分词：即修改搜索引擎为中文分词
（1）在子模块中创建whoosh_cn_backend.py
复制 Lib\site- packages\haystack\backends\whoosh_backend.py 文件，
粘贴到应用目录下（这里是 mysearch）改名为 whoosh_cn_backend.py。
（2）导入模块：from jieba.analyse import ChineseAnalyzer
（3）在166行：查找 analyzer=StemmingAnalyzer() 改为 analyzer=ChineseAnalyzer()
8.生成索引
初始化索引数据：>> python manage.py rebuild_index
9.在需要的模板中创建搜索栏 :
图片1：步骤4.设置数据模板article_text.txt
图片2：步骤3. 创建索引类search_indexes.py 步骤7.设定中文分词whoosh_cn_backend.py
图片3：步骤6.创建结果展示页面，路径和名称固定
在步骤7.中设定中文分词：whoosh_cn_backend.py文件如下
# encoding: utf-8
from __future__ import absolute_import, division, print_function, unicode_literals
from jieba.analyse import ChineseAnalyzer
import json
import os
import re
import shutil
import threading
import warnings
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.utils import six
from django.utils.datetime_safe import datetime
from django.utils.encoding import force_text
from haystack.backends import BaseEngine, BaseSearchBackend, BaseSearchQuery, EmptyResults, log_query
from haystack.constants import DJANGO_CT, DJANGO_ID, ID
from haystack.exceptions import MissingDependency, SearchBackendError, SkipDocument
from haystack.inputs import Clean, Exact, PythonData, Raw
from haystack.models import SearchResult
from haystack.utils import log as logging
from haystack.utils import get_identifier, get_model_ct
from haystack.utils.app_loading import haystack_get_model
try:
import whoosh
except ImportError:
raise MissingDependency("The 'whoosh' backend requires the installation of 'Whoosh'. Please refer to the documentation.")
# Handle minimum requirement.
if not hasattr(whoosh, '__version__') or whoosh.__version__ < (2, 5, 0):
raise MissingDependency("The 'whoosh' backend requires version 2.5.0 or greater.")
# Bubble up the correct error.
from whoosh import index
from whoosh.analysis import StemmingAnalyzer
from whoosh.fields import ID as WHOOSH_ID
from whoosh.fields import BOOLEAN, DATETIME, IDLIST, KEYWORD, NGRAM, NGRAMWORDS, NUMERIC, Schema, TEXT
from whoosh.filedb.filestore import FileStorage, RamStorage
from whoosh.highlight import highlight as whoosh_highlight
from whoosh.highlight import ContextFragmenter, HtmlFormatter
from whoosh.qparser import QueryParser
from whoosh.searching import ResultsPage
from whoosh.writing import AsyncWriter
DATETIME_REGEX = re.compile('^(?P\d{4})-(?P\d{2})-(?P\d{2})T(?P\d{2}):(?P\d{2}):(?P\d{2})(\.\d{3,6}Z?)?$')
LOCALS = threading.local()
LOCALS.RAM_STORE = None
class WhooshHtmlFormatter(HtmlFormatter):
"""
This is a HtmlFormatter simpler than the whoosh.HtmlFormatter.
We use it to have consistent results across backends. Specifically,
Solr, Xapian and Elasticsearch are using this formatting.
"""
template = '<%(tag)s>%(t)s'
class WhooshSearchBackend(BaseSearchBackend):
# Word reserved by Whoosh for special use.
RESERVED_WORDS = (
'AND',
'NOT',
'OR',
'TO',
)
# Characters reserved by Whoosh for special use.
# The '\\' must come first, so as not to overwrite the other slash replacements.
RESERVED_CHARACTERS = (
'\\', '+', '-', '&&', '||', '!', '(', ')', '{', '}',
'[', ']', '^', '"', '~', '*', '?', ':', '.',
)
def __init__(self, connection_alias, **connection_options):
super(WhooshSearchBackend, self).__init__(connection_alias, **connection_options)
self.setup_complete = False
self.use_file_storage = True
self.post_limit = getattr(connection_options, 'POST_LIMIT', 128 * 1024 * 1024)
self.path = connection_options.get('PATH')
if connection_options.get('STORAGE', 'file') != 'file':
self.use_file_storage = False
if self.use_file_storage and not self.path:
raise ImproperlyConfigured("You must specify a 'PATH' in your settings for connection '%s'." % connection_alias)
self.log = logging.getLogger('haystack')
def setup(self):
"""
Defers loading until needed.
"""
from haystack import connections
new_index = False
# Make sure the index is there.
if self.use_file_storage and not os.path.exists(self.path):
os.makedirs(self.path)
new_index = True
if self.use_file_storage and not os.access(self.path, os.W_OK):
raise IOError("The path to your Whoosh index '%s' is not writable for the current user/group." % self.path)
if self.use_file_storage:
self.storage = FileStorage(self.path)
else:
global LOCALS
if getattr(LOCALS, 'RAM_STORE', None) is None:
LOCALS.RAM_STORE = RamStorage()
self.storage = LOCALS.RAM_STORE
self.content_field_name, self.schema = self.build_schema(connections[self.connection_alias].get_unified_index().all_searchfields())
self.parser = QueryParser(self.content_field_name, schema=self.schema)
if new_index is True:
self.index = self.storage.create_index(self.schema)
else:
try:
self.index = self.storage.open_index(schema=self.schema)
except index.EmptyIndexError:
self.index = self.storage.create_index(self.schema)
self.setup_complete = True
def build_schema(self, fields):
schema_fields = {
ID: WHOOSH_ID(stored=True, unique=True),
DJANGO_CT: WHOOSH_ID(stored=True),
DJANGO_ID: WHOOSH_ID(stored=True),
}
# Grab the number of keys that are hard-coded into Haystack.
# We'll use this to (possibly) fail slightly more gracefully later.
initial_key_count = len(schema_fields)
content_field_name = ''
for field_name, field_class in fields.items():
if field_class.is_multivalued:
if field_class.indexed is False:
schema_fields[field_class.index_fieldname] = IDLIST(stored=True, field_boost=field_class.boost)
else:
schema_fields[field_class.index_fieldname] = KEYWORD(stored=True, commas=True, scorable=True, field_boost=field_class.boost)
elif field_class.field_type in ['date', 'datetime']:
schema_fields[field_class.index_fieldname] = DATETIME(stored=field_class.stored, sortable=True)
elif field_class.field_type == 'integer':
schema_fields[field_class.index_fieldname] = NUMERIC(stored=field_class.stored, numtype=int, field_boost=field_class.boost)
elif field_class.field_type == 'float':
schema_fields[field_class.index_fieldname] = NUMERIC(stored=field_class.stored, numtype=float, field_boost=field_class.boost)
elif field_class.field_type == 'boolean':
# Field boost isn't supported on BOOLEAN as of 1.8.2.
schema_fields[field_class.index_fieldname] = BOOLEAN(stored=field_class.stored)
elif field_class.field_type == 'ngram':
schema_fields[field_class.index_fieldname] = NGRAM(minsize=3, maxsize=15, stored=field_class.stored, field_boost=field_class.boost)
elif field_class.field_type == 'edge_ngram':
schema_fields[field_class.index_fieldname] = NGRAMWORDS(minsize=2, maxsize=15, at='start', stored=field_class.stored, field_boost=field_class.boost)
else:
schema_fields[field_class.index_fieldname] = TEXT(stored=True, analyzer=ChineseAnalyzer(), field_boost=field_class.boost, sortable=True)
if field_class.document is True:
content_field_name = field_class.index_fieldname
schema_fields[field_class.index_fieldname].spelling = True
# Fail more gracefully than relying on the backend to die if no fields
# are found.
if len(schema_fields) <= initial_key_count:
raise SearchBackendError("No fields were found in any search_indexes. Please correct this before attempting to search.")
return (content_field_name, Schema(**schema_fields))
def update(self, index, iterable, commit=True):
if not self.setup_complete:
self.setup()
self.index = self.index.refresh()
writer = AsyncWriter(self.index)
for obj in iterable:
try:
doc = index.full_prepare(obj)
except SkipDocument:
self.log.debug(u"Indexing for object `%s` skipped", obj)
else:
# Really make sure it's unicode, because Whoosh won't have it any
# other way.
for key in doc:
doc[key] = self._from_python(doc[key])
# Document boosts aren't supported in Whoosh 2.5.0+.
if 'boost' in doc:
del doc['boost']
try:
writer.update_document(**doc)
except Exception as e:
if not self.silently_fail:
raise
# We'll log the object identifier but won't include the actual object
# to avoid the possibility of that generating encoding errors while
# processing the log message:
self.log.error(u"%s while preparing object for update" % e.__class__.__name__,
exc_info=True, extra={"data": {"index": index,
"object": get_identifier(obj)}})
if len(iterable) > 0:
# For now, commit no matter what, as we run into locking issues otherwise.
writer.commit()
def remove(self, obj_or_string, commit=True):
if not self.setup_complete:
self.setup()
self.index = self.index.refresh()
whoosh_id = get_identifier(obj_or_string)
try:
self.index.delete_by_query(q=self.parser.parse(u'%s:"%s"' % (ID, whoosh_id)))
except Exception as e:
if not self.silently_fail:
raise
self.log.error("Failed to remove document '%s' from Whoosh: %s", whoosh_id, e, exc_info=True)
def clear(self, models=None, commit=True):
if not self.setup_complete:
self.setup()
self.index = self.index.refresh()
if models is not None:
assert isinstance(models, (list, tuple))
try:
if models is None:
self.delete_index()
else:
models_to_delete = []
for model in models:
models_to_delete.append(u"%s:%s" % (DJANGO_CT, get_model_ct(model)))
self.index.delete_by_query(q=self.parser.parse(u" OR ".join(models_to_delete)))
except Exception as e:
if not self.silently_fail:
raise
if models is not None:
self.log.error("Failed to clear Whoosh index of models '%s': %s", ','.join(models_to_delete),
e, exc_info=True)
else:
self.log.error("Failed to clear Whoosh index: %s", e, exc_info=True)
def delete_index(self):
# Per the Whoosh mailing list, if wiping out everything from the index,
# it's much more efficient to simply delete the index files.
if self.use_file_storage and os.path.exists(self.path):
shutil.rmtree(self.path)
elif not self.use_file_storage:
self.storage.clean()
# Recreate everything.
self.setup()
def optimize(self):
if not self.setup_complete:
self.setup()
self.index = self.index.refresh()
self.index.optimize()
def calculate_page(self, start_offset=0, end_offset=None):
# Prevent against Whoosh throwing an error. Requires an end_offset
# greater than 0.
if end_offset is not None and end_offset <= 0:
end_offset = 1
# Determine the page.
page_num = 0
if end_offset is None:
end_offset = 1000000
if start_offset is None:
start_offset = 0
page_length = end_offset - start_offset
if page_length and page_length > 0:
page_num = int(start_offset / page_length)
# Increment because Whoosh uses 1-based page numbers.
page_num += 1
return page_num, page_length
@log_query
def search(self, query_string, sort_by=None, start_offset=0, end_offset=None,
fields='', highlight=False, facets=None, date_facets=None, query_facets=None,
narrow_queries=None, spelling_query=None, within=None,
dwithin=None, distance_point=None, models=None,
limit_to_registered_models=None, result_class=None, **kwargs):
if not self.setup_complete:
self.setup()
# A zero length query should return no results.
if len(query_string) == 0:
return {
'results': [],
'hits': 0,
}
query_string = force_text(query_string)
# A one-character query (non-wildcard) gets nabbed by a stopwords
# filter and should yield zero results.
if len(query_string) <= 1 and query_string != u'*':
return {
'results': [],
'hits': 0,
}
reverse = False
if sort_by is not None:
# Determine if we need to reverse the results and if Whoosh can
# handle what it's being asked to sort by. Reversing is an
# all-or-nothing action, unfortunately.
sort_by_list = []
reverse_counter = 0
for order_by in sort_by:
if order_by.startswith('-'):
reverse_counter += 1
if reverse_counter and reverse_counter != len(sort_by):
raise SearchBackendError("Whoosh requires all order_by fields"
" to use the same sort direction")
for order_by in sort_by:
if order_by.startswith('-'):
sort_by_list.append(order_by[1:])
if len(sort_by_list) == 1:
reverse = True
else:
sort_by_list.append(order_by)
if len(sort_by_list) == 1:
reverse = False
sort_by = sort_by_list
if facets is not None:
warnings.warn("Whoosh does not handle faceting.", Warning, stacklevel=2)
if date_facets is not None:
warnings.warn("Whoosh does not handle date faceting.", Warning, stacklevel=2)
if query_facets is not None:
warnings.warn("Whoosh does not handle query faceting.", Warning, stacklevel=2)
narrowed_results = None
self.index = self.index.refresh()
if limit_to_registered_models is None:
limit_to_registered_models = getattr(settings, 'HAYSTACK_LIMIT_TO_REGISTERED_MODELS', True)
if models and len(models):
model_choices = sorted(get_model_ct(model) for model in models)
elif limit_to_registered_models:
# Using narrow queries, limit the results to only models handled
# with the current routers.
model_choices = self.build_models_list()
else:
model_choices = []
if len(model_choices) > 0:
if narrow_queries is None:
narrow_queries = set()
narrow_queries.add(' OR '.join(['%s:%s' % (DJANGO_CT, rm) for rm in model_choices]))
narrow_searcher = None
if narrow_queries is not None:
# Potentially expensive? I don't see another way to do it in Whoosh...
narrow_searcher = self.index.searcher()
for nq in narrow_queries:
recent_narrowed_results = narrow_searcher.search(self.parser.parse(force_text(nq)),
limit=None)
if len(recent_narrowed_results) <= 0:
return {
'results': [],
'hits': 0,
}
if narrowed_results:
narrowed_results.filter(recent_narrowed_results)
else:
narrowed_results = recent_narrowed_results
self.index = self.index.refresh()
if self.index.doc_count():
searcher = self.index.searcher()
parsed_query = self.parser.parse(query_string)
# In the event of an invalid/stopworded query, recover gracefully.
if parsed_query is None:
return {
'results': [],
'hits': 0,
}
page_num, page_length = self.calculate_page(start_offset, end_offset)
search_kwargs = {
'pagelen': page_length,
'sortedby': sort_by,
'reverse': reverse,
}
# Handle the case where the results have been narrowed.
if narrowed_results is not None:
search_kwargs['filter'] = narrowed_results
try:
raw_page = searcher.search_page(
parsed_query,
page_num,
**search_kwargs
)
except ValueError:
if not self.silently_fail:
raise
return {
'results': [],
'hits': 0,
'spelling_suggestion': None,
}
# Because as of Whoosh 2.5.1, it will return the wrong page of
# results if you request something too high. :(
if raw_page.pagenum < page_num:
return {
'results': [],
'hits': 0,
'spelling_suggestion': None,
}
results = self._process_results(raw_page, highlight=highlight, query_string=query_string, spelling_query=spelling_query, result_class=result_class)
searcher.close()
if hasattr(narrow_searcher, 'close'):
narrow_searcher.close()
return results
else:
if self.include_spelling:
if spelling_query:
spelling_suggestion = self.create_spelling_suggestion(spelling_query)
else:
spelling_suggestion = self.create_spelling_suggestion(query_string)
else:
spelling_suggestion = None
return {
'results': [],
'hits': 0,
'spelling_suggestion': spelling_suggestion,
}
def more_like_this(self, model_instance, additional_query_string=None,
start_offset=0, end_offset=None, models=None,
limit_to_registered_models=None, result_class=None, **kwargs):
if not self.setup_complete:
self.setup()
field_name = self.content_field_name
narrow_queries = set()
narrowed_results = None
self.index = self.index.refresh()
if limit_to_registered_models is None:
limit_to_registered_models = getattr(settings, 'HAYSTACK_LIMIT_TO_REGISTERED_MODELS', True)
if models and len(models):
model_choices = sorted(get_model_ct(model) for model in models)
elif limit_to_registered_models:
# Using narrow queries, limit the results to only models handled
# with the current routers.
model_choices = self.build_models_list()
else:
model_choices = []
if len(model_choices) > 0:
if narrow_queries is None:
narrow_queries = set()
narrow_queries.add(' OR '.join(['%s:%s' % (DJANGO_CT, rm) for rm in model_choices]))
if additional_query_string and additional_query_string != '*':
narrow_queries.add(additional_query_string)
narrow_searcher = None
if narrow_queries is not None:
# Potentially expensive? I don't see another way to do it in Whoosh...
narrow_searcher = self.index.searcher()
for nq in narrow_queries:
recent_narrowed_results = narrow_searcher.search(self.parser.parse(force_text(nq)),
limit=None)
if len(recent_narrowed_results) <= 0:
return {
'results': [],
'hits': 0,
}
if narrowed_results:
narrowed_results.filter(recent_narrowed_results)
else:
narrowed_results = recent_narrowed_results
page_num, page_length = self.calculate_page(start_offset, end_offset)
self.index = self.index.refresh()
raw_results = EmptyResults()
searcher = None
if self.index.doc_count():
query = "%s:%s" % (ID, get_identifier(model_instance))
searcher = self.index.searcher()
parsed_query = self.parser.parse(query)
results = searcher.search(parsed_query)
if len(results):
raw_results = results[0].more_like_this(field_name, top=end_offset)
# Handle the case where the results have been narrowed.
if narrowed_results is not None and hasattr(raw_results, 'filter'):
raw_results.filter(narrowed_results)
try:
raw_page = ResultsPage(raw_results, page_num, page_length)
except ValueError:
if not self.silently_fail:
raise
return {
'results': [],
'hits': 0,
'spelling_suggestion': None,
}
# Because as of Whoosh 2.5.1, it will return the wrong page of
# results if you request something too high. :(
if raw_page.pagenum < page_num:
return {
'results': [],
'hits': 0,
'spelling_suggestion': None,
}
results = self._process_results(raw_page, result_class=result_class)
if searcher:
searcher.close()
if hasattr(narrow_searcher, 'close'):
narrow_searcher.close()
return results
def _process_results(self, raw_page, highlight=False, query_string='', spelling_query=None, result_class=None):
from haystack import connections
results = []
# It's important to grab the hits first before slicing. Otherwise, this
# can cause pagination failures.
hits = len(raw_page)
if result_class is None:
result_class = SearchResult
facets = {}
spelling_suggestion = None
unified_index = connections[self.connection_alias].get_unified_index()
indexed_models = unified_index.get_indexed_models()
for doc_offset, raw_result in enumerate(raw_page):
score = raw_page.score(doc_offset) or 0
app_label, model_name = raw_result[DJANGO_CT].split('.')
additional_fields = {}
model = haystack_get_model(app_label, model_name)
if model and model in indexed_models:
for key, value in raw_result.items():
index = unified_index.get_index(model)
string_key = str(key)
if string_key in index.fields and hasattr(index.fields[string_key], 'convert'):
# Special-cased due to the nature of KEYWORD fields.
if index.fields[string_key].is_multivalued:
if value is None or len(value) is 0:
additional_fields[string_key] = []
else:
additional_fields[string_key] = value.split(',')
else:
additional_fields[string_key] = index.fields[string_key].convert(value)
else:
additional_fields[string_key] = self._to_python(value)
del(additional_fields[DJANGO_CT])
del(additional_fields[DJANGO_ID])
if highlight:
sa = StemmingAnalyzer()
formatter = WhooshHtmlFormatter('em')
terms = [token.text for token in sa(query_string)]
whoosh_result = whoosh_highlight(
additional_fields.get(self.content_field_name),
terms,
sa,
ContextFragmenter(),
formatter
)
additional_fields['highlighted'] = {
self.content_field_name: [whoosh_result],
}
result = result_class(app_label, model_name, raw_result[DJANGO_ID], score, **additional_fields)
results.append(result)
else:
hits -= 1
if self.include_spelling:
if spelling_query:
spelling_suggestion = self.create_spelling_suggestion(spelling_query)
else:
spelling_suggestion = self.create_spelling_suggestion(query_string)
return {
'results': results,
'hits': hits,
'facets': facets,
'spelling_suggestion': spelling_suggestion,
}
def create_spelling_suggestion(self, query_string):
spelling_suggestion = None
reader = self.index.reader()
corrector = reader.corrector(self.content_field_name)
cleaned_query = force_text(query_string)
if not query_string:
return spelling_suggestion
# Clean the string.
for rev_word in self.RESERVED_WORDS:
cleaned_query = cleaned_query.replace(rev_word, '')
for rev_char in self.RESERVED_CHARACTERS:
cleaned_query = cleaned_query.replace(rev_char, '')
# Break it down.
query_words = cleaned_query.split()
suggested_words = []
for word in query_words:
suggestions = corrector.suggest(word, limit=1)
if len(suggestions) > 0:
suggested_words.append(suggestions[0])
spelling_suggestion = ' '.join(suggested_words)
return spelling_suggestion
def _from_python(self, value):
"""
Converts Python values to a string for Whoosh.
Code courtesy of pysolr.
"""
if hasattr(value, 'strftime'):
if not hasattr(value, 'hour'):
value = datetime(value.year, value.month, value.day, 0, 0, 0)
elif isinstance(value, bool):
if value:
value = 'true'
else:
value = 'false'
elif isinstance(value, (list, tuple)):
value = u','.join([force_text(v) for v in value])
elif isinstance(value, (six.integer_types, float)):
# Leave it alone.
pass
else:
value = force_text(value)
return value
def _to_python(self, value):
"""
Converts values from Whoosh to native Python values.
A port of the same method in pysolr, as they deal with data the same way.
"""
if value == 'true':
return True
elif value == 'false':
return False
if value and isinstance(value, six.string_types):
possible_datetime = DATETIME_REGEX.search(value)
if possible_datetime:
date_values = possible_datetime.groupdict()
for dk, dv in date_values.items():
date_values[dk] = int(dv)
return datetime(date_values['year'], date_values['month'], date_values['day'], date_values['hour'], date_values['minute'], date_values['second'])
try:
# Attempt to use json to load the values.
converted_value = json.loads(value)
# Try to handle most built-in types.
if isinstance(converted_value, (list, tuple, set, dict, six.integer_types, float, complex)):
return converted_value
except:
# If it fails (SyntaxError or its ilk) or we don't trust it,
# continue on.
pass
return value
class WhooshSearchQuery(BaseSearchQuery):
def _convert_datetime(self, date):
if hasattr(date, 'hour'):
return force_text(date.strftime('%Y%m%d%H%M%S'))
else:
return force_text(date.strftime('%Y%m%d000000'))
def clean(self, query_fragment):
"""
Provides a mechanism for sanitizing user input before presenting the
value to the backend.
Whoosh 1.X differs here in that you can no longer use a backslash
to escape reserved characters. Instead, the whole word should be
quoted.
"""
words = query_fragment.split()
cleaned_words = []
for word in words:
if word in self.backend.RESERVED_WORDS:
word = word.replace(word, word.lower())
for char in self.backend.RESERVED_CHARACTERS:
if char in word:
word = "'%s'" % word
break
cleaned_words.append(word)
return ' '.join(cleaned_words)
def build_query_fragment(self, field, filter_type, value):
from haystack import connections
query_frag = ''
is_datetime = False
if not hasattr(value, 'input_type_name'):
# Handle when we've got a ``ValuesListQuerySet``...
if hasattr(value, 'values_list'):
value = list(value)
if hasattr(value, 'strftime'):
is_datetime = True
if isinstance(value, six.string_types) and value != ' ':
# It's not an ``InputType``. Assume ``Clean``.
value = Clean(value)
else:
value = PythonData(value)
# Prepare the query using the InputType.
prepared_value = value.prepare(self)
if not isinstance(prepared_value, (set, list, tuple)):
# Then convert whatever we get back to what pysolr wants if needed.
prepared_value = self.backend._from_python(prepared_value)
# 'content' is a special reserved word, much like 'pk' in
# Django's ORM layer. It indicates 'no special field'.
if field == 'content':
index_fieldname = ''
else:
index_fieldname = u'%s:' % connections[self._using].get_unified_index().get_index_fieldname(field)
filter_types = {
'content': '%s',
'contains': '*%s*',
'endswith': "*%s",
'startswith': "%s*",
'exact': '%s',
'gt': "{%s to}",
'gte': "[%s to]",
'lt': "{to %s}",
'lte': "[to %s]",
'fuzzy': u'%s~',
}
if value.post_process is False:
query_frag = prepared_value
else:
if filter_type in ['content', 'contains', 'startswith', 'endswith', 'fuzzy']:
if value.input_type_name == 'exact':
query_frag = prepared_value
else:
# Iterate over terms & incorportate the converted form of each into the query.
terms = []
if isinstance(prepared_value, six.string_types):
possible_values = prepared_value.split(' ')
else:
if is_datetime is True:
prepared_value = self._convert_datetime(prepared_value)
possible_values = [prepared_value]
for possible_value in possible_values:
terms.append(filter_types[filter_type] % self.backend._from_python(possible_value))
if len(terms) == 1:
query_frag = terms[0]
else:
query_frag = u"(%s)" % " AND ".join(terms)
elif filter_type == 'in':
in_options = []
for possible_value in prepared_value:
is_datetime = False
if hasattr(possible_value, 'strftime'):
is_datetime = True
pv = self.backend._from_python(possible_value)
if is_datetime is True:
pv = self._convert_datetime(pv)
if isinstance(pv, six.string_types) and not is_datetime:
in_options.append('"%s"' % pv)
else:
in_options.append('%s' % pv)
query_frag = "(%s)" % " OR ".join(in_options)
elif filter_type == 'range':
start = self.backend._from_python(prepared_value[0])
end = self.backend._from_python(prepared_value[1])
if hasattr(prepared_value[0], 'strftime'):
start = self._convert_datetime(start)
if hasattr(prepared_value[1], 'strftime'):
end = self._convert_datetime(end)
query_frag = u"[%s to %s]" % (start, end)
elif filter_type == 'exact':
if value.input_type_name == 'exact':
query_frag = prepared_value
else:
prepared_value = Exact(prepared_value).prepare(self)
query_frag = filter_types[filter_type] % prepared_value
else:
if is_datetime is True:
prepared_value = self._convert_datetime(prepared_value)
query_frag = filter_types[filter_type] % prepared_value
if len(query_frag) and not isinstance(value, Raw):
if not query_frag.startswith('(') and not query_frag.endswith(')'):
query_frag = "(%s)" % query_frag
return u"%s%s" % (index_fieldname, query_frag)
class WhooshEngine(BaseEngine):
backend = WhooshSearchBackend
query = WhooshSearchQuery