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django-全文检索

發(fā)布時間：2025/7/25 编程问答 25 豆豆

生活随笔收集整理的這篇文章主要介紹了 django-全文检索小編覺得挺不錯的,現(xiàn)在分享給大家,幫大家做個參考.

全文檢索不同于特定字段的模糊查詢，使用全文檢索的效率更高，并且能夠?qū)τ谥形倪M行分詞處理

需要的第三方庫：

haystack：django的一個包，可以方便地對model里面的內(nèi)容進行索引、搜索，設(shè)計為支持whoosh,solr,Xapian,Elasticsearc四種全文檢索引擎后端，屬于一種全文檢索的框架
whoosh：純Python編寫的全文搜索引擎，雖然性能比不上sphinx、xapian、Elasticsearc等，但是無二進制包，程序不會莫名其妙的崩潰，對于小型的站點，whoosh已經(jīng)足夠使用
jieba：一款免費的中文分詞包

操作

首先pip安裝包

pip install django-haystack
pip install whoosh
pip install jieba

設(shè)置settings

添加應(yīng)用：

INSTALLED_APPS = (...'haystack', )

添加搜索引擎：

HAYSTACK_CONNECTIONS = {'default': {'ENGINE': 'haystack.backends.whoosh_cn_backend.WhooshEngine','PATH': os.path.join(BASE_DIR, 'whoosh_index'),} }#自動生成索引 HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
#每一頁顯示多少數(shù)據(jù) HAYSTACK_SEARCH_RESULTS_PER_PAGE = 18 ?

添加url：

urlpatterns = [...url(r'^search/', include('haystack.urls')), ]

在應(yīng)用目錄下建立search_indexes.py

# coding=utf-8 from haystack import indexes from models import GoodsInfoclass GoodsInfoIndex(indexes.SearchIndex, indexes.Indexable):text = indexes.CharField(document=True, use_template=True)def get_model(self):return GoodsInfodef index_queryset(self, using=None):return self.get_model().objects.all()

在目錄“templates/search/indexes/應(yīng)用名稱/”下創(chuàng)建“模型類名稱_text.txt”文件

#goodsinfo_text.txt，這里列出了要對哪些列的內(nèi)容進行檢索,模型類中的某些字段 {{ object.gName }} {{ object.gSubName }} {{ object.gDes }}

在目錄“templates/search/”下建立search.html

<!DOCTYPE html> <html> <head><title></title> </head> <body> {% if query %}<h3>搜索結(jié)果如下：</h3>{% for result in page.object_list %}<a href="/{{ result.object.id }}/">{{ result.object.gName }}</a><br/>{% empty %}<p>沒找到</p>{% endfor %}{% if page.has_previous or page.has_next %}<div>{% if page.has_previous %}<a href="?q={{ query }}&page={{ page.previous_page_number }}">{% endif %}« 上一頁{% if page.has_previous %}</a>{% endif %}|{% if page.has_next %}<a href="?q={{ query }}&page={{ page.next_page_number }}">{% endif %}下一頁 »{% if page.has_next %}</a>{% endif %}</div>{% endif %} {% endif %} </body> </html>

建立ChineseAnalyzer.py文件

保存在haystack的安裝文件夾下，路徑如“/home/python/.virtualenvs/django_py2/lib/python2.7/site-packages/haystack/backends”

import jieba from whoosh.analysis import Tokenizer, Tokenclass ChineseTokenizer(Tokenizer):def __call__(self, value, positions=False, chars=False,keeporiginal=False, removestops=True,start_pos=0, start_char=0, mode='', **kwargs):t = Token(positions, chars, removestops=removestops, mode=mode,**kwargs)seglist = jieba.cut(value, cut_all=True)for w in seglist:t.original = t.text = wt.boost = 1.0if positions:t.pos = start_pos + value.find(w)if chars:t.startchar = start_char + value.find(w)t.endchar = start_char + value.find(w) + len(w)yield tdef ChineseAnalyzer():return ChineseTokenizer()

復(fù)制whoosh_backend.py文件，改名為whoosh_cn_backend.py

from .ChineseAnalyzer import ChineseAnalyzer 查找 analyzer=StemmingAnalyzer() 改為 analyzer=ChineseAnalyzer()

生成索引

初始化索引：

python manage.py rebuild_index

在模板中創(chuàng)建搜索欄

關(guān)于全文索引使用的固定參數(shù)一些說明：

我們打開haystack第三方包中的urls文件

haystack----urls.py # encoding: utf-8from __future__ import absolute_import, division, print_function, unicode_literalsfrom django.conf.urls import urlfrom haystack.views import SearchViewurlpatterns = [url(r'^$', SearchView(), name='haystack_search'), ]

然后進入haystack.views 文件

#這里將搜索顯示的數(shù)據(jù)默認為20個
RESULTS_PER_PAGE = getattr(settings, 'HAYSTACK_SEARCH_RESULTS_PER_PAGE', 20)
#在search文件下的search template = 'search/search.html' extra_context = {} query = '' results = EmptySearchQuerySet() request = None form = None results_per_page = RESULTS_PER_PAGE

更多詳情請看

haystack.views.py

# encoding: utf-8from __future__ import absolute_import, division, print_function, unicode_literalsfrom django.conf import settings from django.core.paginator import InvalidPage, Paginator from django.http import Http404 from django.shortcuts import renderfrom haystack.forms import FacetedSearchForm, ModelSearchForm from haystack.query import EmptySearchQuerySetRESULTS_PER_PAGE = getattr(settings, 'HAYSTACK_SEARCH_RESULTS_PER_PAGE', 20)class SearchView(object):template = 'search/search.html'extra_context = {}query = ''results = EmptySearchQuerySet()request = Noneform = Noneresults_per_page = RESULTS_PER_PAGEdef __init__(self, template=None, load_all=True, form_class=None, searchqueryset=None, results_per_page=None):self.load_all = load_allself.form_class = form_classself.searchqueryset = searchquerysetif form_class is None:self.form_class = ModelSearchFormif not results_per_page is None:self.results_per_page = results_per_pageif template:self.template = templatedef __call__(self, request):"""Generates the actual response to the search.Relies on internal, overridable methods to construct the response."""self.request = requestself.form = self.build_form()self.query = self.get_query()self.results = self.get_results()return self.create_response()def build_form(self, form_kwargs=None):"""Instantiates the form the class should use to process the search query."""data = Nonekwargs = {'load_all': self.load_all,}if form_kwargs:kwargs.update(form_kwargs)if len(self.request.GET):data = self.request.GETif self.searchqueryset is not None:kwargs['searchqueryset'] = self.searchquerysetreturn self.form_class(data, **kwargs)def get_query(self):"""Returns the query provided by the user.Returns an empty string if the query is invalid."""if self.form.is_valid():return self.form.cleaned_data['q']return ''def get_results(self):"""Fetches the results via the form.Returns an empty list if there's no query to search with."""return self.form.search()def build_page(self):"""Paginates the results appropriately.In case someone does not want to use Django's built-in pagination, itshould be a simple matter to override this method to do what they wouldlike."""try:page_no = int(self.request.GET.get('page', 1))except (TypeError, ValueError):raise Http404("Not a valid number for page.")if page_no < 1:raise Http404("Pages should be 1 or greater.")start_offset = (page_no - 1) * self.results_per_pageself.results[start_offset:start_offset + self.results_per_page]paginator = Paginator(self.results, self.results_per_page)try:page = paginator.page(page_no)except InvalidPage:raise Http404("No such page!")return (paginator, page)def extra_context(self):"""Allows the addition of more context variables as needed.Must return a dictionary."""return {}def get_context(self):(paginator, page) = self.build_page()context = {'query': self.query,'form': self.form,'page': page,'paginator': paginator,'suggestion': None,}if hasattr(self.results, 'query') and self.results.query.backend.include_spelling:context['suggestion'] = self.form.get_suggestion()context.update(self.extra_context())return contextdef create_response(self):"""Generates the actual HttpResponse to send back to the user."""context = self.get_context()return render(self.request, self.template, context)def search_view_factory(view_class=SearchView, *args, **kwargs):def search_view(request):return view_class(*args, **kwargs)(request)return search_viewclass FacetedSearchView(SearchView):def __init__(self, *args, **kwargs):# Needed to switch out the default form class.if kwargs.get('form_class') is None:kwargs['form_class'] = FacetedSearchFormsuper(FacetedSearchView, self).__init__(*args, **kwargs)def build_form(self, form_kwargs=None):if form_kwargs is None:form_kwargs = {}# This way the form can always receive a list containing zero or more# facet expressions:form_kwargs['selected_facets'] = self.request.GET.getlist("selected_facets")return super(FacetedSearchView, self).build_form(form_kwargs)def extra_context(self):extra = super(FacetedSearchView, self).extra_context()extra['request'] = self.requestextra['facets'] = self.results.facet_counts()return extradef basic_search(request, template='search/search.html', load_all=True, form_class=ModelSearchForm, searchqueryset=None, extra_context=None, results_per_page=None):"""A more traditional view that also demonstrate an alternativeway to use Haystack.Useful as an example of for basing heavily custom views off of.Also has the benefit of thread-safety, which the ``SearchView`` class maynot be.Template:: ``search/search.html``Context::* formAn instance of the ``form_class``. (default: ``ModelSearchForm``)* pageThe current page of search results.* paginatorA paginator instance for the results.* queryThe query received by the form."""query = ''results = EmptySearchQuerySet()if request.GET.get('q'):form = form_class(request.GET, searchqueryset=searchqueryset, load_all=load_all)if form.is_valid():query = form.cleaned_data['q']results = form.search()else:form = form_class(searchqueryset=searchqueryset, load_all=load_all)paginator = Paginator(results, results_per_page or RESULTS_PER_PAGE)try:page = paginator.page(int(request.GET.get('page', 1)))except InvalidPage:raise Http404("No such page of results!")context = {'form': form,'page': page,'paginator': paginator,'query': query,'suggestion': None,}if results.query.backend.include_spelling:context['suggestion'] = form.get_suggestion()if extra_context:context.update(extra_context)return render(request, template, context) View Code

轉(zhuǎn)載于:https://www.cnblogs.com/welan/p/9231430.html

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