1.前提准备
环境介绍
haystack是django的开源搜索框架,该框架支持Solr,Elasticsearch,Whoosh,*Xapian*搜索引擎,不用更改代码,直接切换引擎,减少代码量。
搜索引擎使用Whoosh,这是一个由纯Python实现的全文搜索引擎,没有二进制文件等,比较小巧,配置比较简单,当然性能自然略低。whoosh和xapian的性能差距还是比较明显。索引和搜索的速度有近4倍的差距,在full cache情况下的性能差距更是达到了60倍。
中文分词+,由于Whoosh自带的是英文分词,对中文的分词支持不是太好,故用jieba替换whoosh的分词组件。
Elasticsearch:开源的搜索引擎,本文版本为7.6.0
其他:Python3.6.5, Django2.2
安装环境
pip3 install django==2.2 -i https://pypi.douban.com/simplepip3 install whoosh -i https://pypi.douban.com/simplepip3 install django-haystack -i https://pypi.douban.com/simplepip3 install jieba -i https://pypi.douban.com/simplepip3 install pymysql -i https://pypi.douban.com/simplepip3 install elasticsearch==7.6.0 -i https://pypi.douban.com/simple/
项目结构
- Project - Project - settings.py - blog - models.py
表结构
models.py
from django.db import modelsclass UserInfo(models.Model): username = models.CharField(verbose_name='用户名', max_length=225) def __str__(self): return self.usernameclass Tag(models.Model): name = models.CharField(verbose_name='标签名称', max_length=225) def __str__(self): return self.nameclass Article(models.Model): title = models.CharField(verbose_name='标题', max_length=225) content = models.CharField(verbose_name='内容', max_length=225) # 外键 username = models.ForeignKey(verbose_name='用户', to='UserInfo', on_delete=models.DO_NOTHING) tag = models.ForeignKey(verbose_name='标签', to='Tag', on_delete=models.DO_NOTHING) def __str__(self): return self.title
图解
本文优势
集全网的django+django-haystack+Whoosh的总结,取其精华,去其糟粕,加入了新的注解。
如果你想你的es或者Whoosh集成到django上,那你来对地方了
django+django-haystack+Whoosh+Jieba+mysql
1. setting.py配置
# 数据库配置DATABASES = { 'default': { 'ENGINE': 'django.db.backends.mysql', 'NAME': 'dj_ha', 'USER': 'root', 'PASSWORD': 'foobared', 'HOST': '106.14.42.253', 'PORT': '11111', }}# appINSTALLED_APPS = [ 'haystack', ]# 本教程使用的是Whoosh,故配置如下HAYSTACK_CONNECTIONS = { 'default': { 'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine', 'PATH': os.path.join(os.path.dirname(__file__), 'whoosh_index'), },}# 自动更新索引HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'# 设置每页显示的数目,默认为20,可以自己修改HAYSTACK_SEARCH_RESULTS_PER_PAGE = 8
2. 为表模型创建索引,search_indexes.py
1. 如果你想针对某个app,例如blog做全文检索,则必须在blog的目录下面,建立search_indexes.py文件,文件名不能修改,必须叫search_indexes.py
from haystack import indexesfrom .models import Article# ArticleIndex:固定写法 表名Indexclass ArticleIndex(indexes.SearchIndex, indexes.Indexable): # 固定写法 document=True:haystack和搜索引擎,将给text字段分词,建立索引,使用此字段的内容作为索引进行检索 # use_template=True,使用自己的模板,与document=True进行搭配,自定义检索字段模板(允许谁可以被全文检索,就是谁被建立索引) text = indexes.CharField(document=True, use_template=True) # 以下字段作为辅助数据,便于调用,最后也不知道怎么辅助,我注释了,也不影响搜索 # title:写入引擎的字段名,model_attr='title':相对应的表模型字段名, title = indexes.CharField(model_attr='title') content = indexes.CharField(model_attr='content') username = indexes.CharField(model_attr='username') tag = indexes.CharField(model_attr='tag') def get_model(self): # 需要建立索引的模型 return Article def index_queryset(self, using=None): """Used when the entire index for model is updated.""" # 写入引擎的数据,必须返回queryset类型 return self.get_model().objects.all()
3. 创建被检索的模板(允许谁可以全文检索)
这个数据模板的作用是对Article.title, Article.content,Article.username.username
这三个字段建立索引,当检索的时候会对这三个字段的内容,做全文检索匹配。
数据模板的路径为yourapp/templates/search/indexes/yourapp/note_text.txt,
例如本例子为blog/templates/search/indexes/blog/article_text.txt 文件名必须为要索引的小写模型类名_text.txt
{{ object.title }}{{ object.content }}{{ object.username.username }}
4. 路由
urls.py配置(用内置的视图,后期可以自定义,本文也有介绍)
# urls.pyfrom django.contrib import adminfrom django.urls import path, include, re_pathurlpatterns = [ path('admin/', admin.site.urls), # 配置的搜索路由,路由可以自定义,include('haystack.urls')固定 re_path(r'^search/', include('haystack.urls')),]
haystack.urls的内容(内置的,只是我拉出来,让你看一下,不需要进行修改)
from django.urls import pathfrom haystack.views import SearchViewurlpatterns = [path("", SearchView(), name="haystack_search")]
5.search.html
SearchView()视图函数默认使用的html模板为当前app目录下,
路径为app名称,/templates/search/search.html
所以需要在blog/templates/search/下添加search.html文件,内容为
search.html(原生)
Search
span.highlighted { color: red; }{% load highlight %} {{ form.as_table }} {# {{ form.title.label }}#}
{% if query %} 返回结果
{% for result in page.object_list %} {# { result.object.get_absolute_url }}">{{ result.object.title }}#} { result.object.get_absolute_url }}">{% highlight result.object.title with query %}
{% highlight result.object.content with query %} {# {{ result.object.content }}#} {% empty %} 没有查询到结果!!!
{% endfor %} {% if page.has_previous or page.has_next %} {% if page.has_previous %}{ result.summary }}被高亮处理后的长度{% highlight result.summary with query max_length 40 %} # 5.自定义使用(后面会介绍)# 5.4格式{% myhighlight with [css_class "class_name"] [html_tag "span"] [max_length 200] [start_head True] %}# 5.2使用一{% myhighlight result.object.content with query css_class "highlighted" html_tag "span" max_length 200 start_head True %}# 5.3自定义二{% myhighlight result.object.content with query css_class "highlighted" start_head True %}
7.自定义
自定义返回内容
在app下新建一个文件名称search_views
# 重写SearchView,实现自定义内容# blog/search_views.pyfrom haystack.views import SearchView# 导入模块from .models import *class MySeachView(SearchView): def extra_context(self): # 重载extra_context来添加额外的context内容 context = super(MySeachView, self).extra_context() my_str = '111' context['my_str'] = my_str # print(context) return context
修改路由
from django.contrib import adminfrom django.urls import path, include, re_pathfrom blog import search_viewsurlpatterns = [ path('admin/', admin.site.urls), # 原生的 # re_path(r'^search/', include('haystack.urls')), # 自己的 re_path(r'^search/', search_views.MySeachView(), name='haystack_search'),]
前端使用
圆明园:{{ my_str }}
自定义search.html模板
1. 保证有一个from,get请求,input标签的name=q,value=Search,
自定义高亮显示(原生的会省略)
新建文件夹templatetags
添加blog/templatetags/my_filters_and_tags.py 文件和 blog/templatetags/highlighting.py 文件,
内容如下(源码分别位于haystack/templatetags/lighlight.py 和 haystack/utils/lighlighting.py 中):
my_filters_and_tags.py
# encoding: utf-8from __future__ import absolute_import, division, print_function, unicode_literals from django import templatefrom django.conf import settingsfrom django.core.exceptions import ImproperlyConfiguredfrom django.utils import six from haystack.utils import importlib register = template.Library() class HighlightNode(template.Node): def __init__(self, text_block, query, html_tag=None, css_class=None, max_length=None, start_head=None): self.text_block = template.Variable(text_block) self.query = template.Variable(query) self.html_tag = html_tag self.css_class = css_class self.max_length = max_length self.start_head = start_head if html_tag is not None: self.html_tag = template.Variable(html_tag) if css_class is not None: self.css_class = template.Variable(css_class) if max_length is not None: self.max_length = template.Variable(max_length) if start_head is not None: self.start_head = template.Variable(start_head) def render(self, context): text_block = self.text_block.resolve(context) query = self.query.resolve(context) kwargs = {} if self.html_tag is not None: kwargs['html_tag'] = self.html_tag.resolve(context) if self.css_class is not None: kwargs['css_class'] = self.css_class.resolve(context) if self.max_length is not None: kwargs['max_length'] = self.max_length.resolve(context) if self.start_head is not None: kwargs['start_head'] = self.start_head.resolve(context) # Handle a user-defined highlighting function. if hasattr(settings, 'HAYSTACK_CUSTOM_HIGHLIGHTER') and settings.HAYSTACK_CUSTOM_HIGHLIGHTER: # Do the import dance. try: path_bits = settings.HAYSTACK_CUSTOM_HIGHLIGHTER.split('.') highlighter_path, highlighter_classname = '.'.join(path_bits[:-1]), path_bits[-1] highlighter_module = importlib.import_module(highlighter_path) highlighter_class = getattr(highlighter_module, highlighter_classname) except (ImportError, AttributeError) as e: raise ImproperlyConfigured("The highlighter '%s' could not be imported: %s" % (settings.HAYSTACK_CUSTOM_HIGHLIGHTER, e)) else: from .highlighting import Highlighter highlighter_class = Highlighter highlighter = highlighter_class(query, **kwargs) highlighted_text = highlighter.highlight(text_block) return highlighted_text @register.tagdef myhighlight(parser, token): """ Takes a block of text and highlights words from a provided query within that block of text. Optionally accepts arguments to provide the HTML tag to wrap highlighted word in, a CSS class to use with the tag and a maximum length of the blurb in characters. Syntax:: {% highlight with [css_class "class_name"] [html_tag "span"] [max_length 200] %} Example:: # Highlight summary with default behavior. {% highlight result.summary with request.query %} # Highlight summary but wrap highlighted words with a div and the # following CSS class. {% highlight result.summary with request.query html_tag "div" css_class "highlight_me_please" %} # Highlight summary but only show 40 characters. {% highlight result.summary with request.query max_length 40 %} """ bits = token.split_contents() tag_name = bits[0] if not len(bits) % 2 == 0: raise template.TemplateSyntaxError(u"'%s' tag requires valid pairings arguments." % tag_name) text_block = bits[1] if len(bits) < 4: raise template.TemplateSyntaxError(u"'%s' tag requires an object and a query provided by 'with'." % tag_name) if bits[2] != 'with': raise template.TemplateSyntaxError(u"'%s' tag's second argument should be 'with'." % tag_name) query = bits[3] arg_bits = iter(bits[4:]) kwargs = {} for bit in arg_bits: if bit == 'css_class': kwargs['css_class'] = six.next(arg_bits) if bit == 'html_tag': kwargs['html_tag'] = six.next(arg_bits) if bit == 'max_length': kwargs['max_length'] = six.next(arg_bits) if bit == 'start_head': kwargs['start_head'] = six.next(arg_bits) return HighlightNode(text_block, query, **kwargs)
highlighting.py
# encoding: utf-8 from __future__ import absolute_import, division, print_function, unicode_literals from django.utils.html import strip_tags class Highlighter(object): #默认值 css_class = 'highlighted' html_tag = 'span' max_length = 200 start_head = False text_block = '' def __init__(self, query, **kwargs): self.query = query if 'max_length' in kwargs: self.max_length = int(kwargs['max_length']) if 'html_tag' in kwargs: self.html_tag = kwargs['html_tag'] if 'css_class' in kwargs: self.css_class = kwargs['css_class'] if 'start_head' in kwargs: self.start_head = kwargs['start_head'] self.query_words = set([word.lower() for word in self.query.split() if not word.startswith('-')]) def highlight(self, text_block): self.text_block = strip_tags(text_block) highlight_locations = self.find_highlightable_words() start_offset, end_offset = self.find_window(highlight_locations) return self.render_html(highlight_locations, start_offset, end_offset) def find_highlightable_words(self): # Use a set so we only do this once per unique word. word_positions = {} # Pre-compute the length. end_offset = len(self.text_block) lower_text_block = self.text_block.lower() for word in self.query_words: if not word in word_positions: word_positions[word] = [] start_offset = 0 while start_offset self.max_length: best_start = words_found[:-1][0] best_end = best_start + self.max_length for count, start in enumerate(words_found[:-1]): current_density = 1 for end in words_found[count + 1:]: if end - start highest_density: best_start = start best_end = start + self.max_length highest_density = current_density return (best_start, best_end) def render_html(self, highlight_locations=None, start_offset=None, end_offset=None): # Start by chopping the block down to the proper window. #text_block为内容,start_offset,end_offset分别为第一个匹配query开始和按长度截断位置 text = self.text_block[start_offset:end_offset] # Invert highlight_locations to a location -> term list term_list = [] for term, locations in highlight_locations.items(): term_list += [(loc - start_offset, term) for loc in locations] loc_to_term = sorted(term_list) # Prepare the highlight template if self.css_class: hl_start = '' % (self.html_tag, self.css_class) else: hl_start = '' % (self.html_tag) hl_end = '' % self.html_tag # Copy the part from the start of the string to the first match, # and there replace the match with a highlighted version. #matched_so_far最终求得为text中最后一个匹配query的结尾 highlighted_chunk = "" matched_so_far = 0 prev = 0 prev_str = "" for cur, cur_str in loc_to_term: # This can be in a different case than cur_str actual_term = text[cur:cur + len(cur_str)] # Handle incorrect highlight_locations by first checking for the term if actual_term.lower() == cur_str: if cur 0 and not self.start_head: highlighted_chunk = '...%s' % highlighted_chunk if end_offset < len(self.text_block): highlighted_chunk = '%s...' % highlighted_chunk #可见到目前为止还不包含start_offset前面的,即第一个匹配的前面的部分(text_block[:start_offset]),如需展示(当start_head为True时)便加上 if self.start_head: highlighted_chunk = self.text_block[:start_offset] + highlighted_chunk return highlighted_chunk
前端使用
span.highlighted { color: red; }{% load my_filters_and_tags %}{% myhighlight result.object.content with query css_class "highlighted" html_tag "span" max_length 200 start_head True %}
8. 目前位置搜索已经完成,可以重建索引,同步数据,测试一下
python manage.py rebuild_index
9.jieba分词器配置
9.1先从python包中复制whoosh_backend.py到app中,并改名为whoosh_cn_backend.py
文件路径:\site-packages\haystack\backends\whoosh_backend.py
9.2 对whoosh_cn_backend.py做以下修改:
1、导入 ChineseAnalyzefrom jieba.analyse import ChineseAnalyzer2、替换schema_fields[field_class.index_fieldname] = TEXT(下的analyzeranalyzer=ChineseAnalyzer(),
9.3在django的配置文件中,修改搜索引擎
HAYSTACK_CONNECTIONS = { 'default': { # 设置haystack的搜索引擎 'ENGINE': 'blog.whoosh_cn_backend.WhooshEngine', # 'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine', # 设置索引文件的位置 'PATH': os.path.join(BASE_DIR, 'whoosh_index'), }}
10 django+django-haystack+Elasticsearch7.5+ik+mysql
10.0 切换成es引擎,除了settings.py和把jieba换成ik,其他步骤跟上面的都一样
如果一开始,就是奔着es+ik来的,那步骤9 jieba分词器配置不用看,直接从步骤8跳到这里来
10.1 安装es,ik
基于docker安装Elasticsearch+ElasticSearch-Head+IK分词器_骑台风走的博客-CSDN博客基于docker安装Elasticsearch+ElasticSearch-Head+IK分词器https://blog.csdn.net/qq_52385631/article/details/126567059″ />
from haystack.backends.elasticsearch7_backend import Elasticsearch7SearchBackend, Elasticsearch7SearchEngine"""分析器主要有两种情况会被使用:第一种是插入文档时,将text类型的字段做分词然后插入倒排索引,第二种就是在查询时,先对要查询的text类型的输入做分词,再去倒排索引搜索如果想要让 索引 和 查询 时使用不同的分词器,ElasticSearch也是能支持的,只需要在字段上加上search_analyzer参数在索引时,只会去看字段有没有定义analyzer,有定义的话就用定义的,没定义就用ES预设的在查询时,会先去看字段有没有定义search_analyzer,如果没有定义,就去看有没有analyzer,再没有定义,才会去使用ES预设的"""DEFAULT_FIELD_MAPPING = { "type": "text", "analyzer": "ik_max_word", # "analyzer": "ik_smart", "search_analyzer": "ik_smart"}class Elasticsearc7IkSearchBackend(Elasticsearch7SearchBackend): def __init__(self, *args, **kwargs): self.DEFAULT_SETTINGS['settings']['analysis']['analyzer']['ik_analyzer'] = { "type": "custom", "tokenizer": "ik_max_word", # "tokenizer": "ik_smart", } super(Elasticsearc7IkSearchBackend, self).__init__(*args, **kwargs)class Elasticsearch7IkSearchEngine(Elasticsearch7SearchEngine): backend = Elasticsearc7IkSearchBackend
10.3 修改settings.py(切换成功)
# es 7.x配置HAYSTACK_CONNECTIONS = { 'default': { # 'ENGINE': 'haystack.backends.elasticsearch7_backend.Elasticsearch7SearchEngine', 'ENGINE': 'blog.elasticsearch_ik_backend.Elasticsearch7IkSearchEngine', # 'URL': 'http://106.14.42.253:9200/', 'URL': 'http://106.14.42.253:9200/', # elasticsearch建立的索引库的名称,一般使用项目名作为索引库 'INDEX_NAME': 'elastic_new', },}
10.4 重建索引,同步数据
python manage.py rebuild_index
10.5 补充
10.5.1 未成功切换成ik
haystack 原先加载的是…\venv\Lib\site-packages\haystack\backends文件夹下的elasticsearch7_backend.py文件,打开即可看到 elasticsearch7 引擎的默认配置
若用上述方法建立出来的索引字段仍使用snowball 分词器,则将原先elasticsearch7_backend.py文件中的DEFAULT_FIELD_MAPPING也修改为 ik 分词器(或许是因为版本问题)
位置:D:\py_virtualenv\dj_ha\Lib\site-packages\haystack\backends\elasticsearch7_backend.py
修改内容:
DEFAULT_FIELD_MAPPING = { "type": "text", "analyzer": "ik_max_word", "search_analyzer": "ik_smart",}
10.5.2 es6版本加入ik,重写引擎
from haystack.backends.elasticsearch_backend import ElasticsearchSearchBackendfrom haystack.backends.elasticsearch_backend import ElasticsearchSearchEngineclass IKSearchBackend(ElasticsearchSearchBackend): DEFAULT_ANALYZER = "ik_max_word" # 这里将 es 的 默认 analyzer 设置为 ik_max_word def __init__(self, connection_alias, **connection_options): super().__init__(connection_alias, **connection_options) def build_schema(self, fields): content_field_name, mapping = super(IKSearchBackend, self).build_schema(fields) for field_name, field_class in fields.items(): field_mapping = mapping[field_class.index_fieldname] if field_mapping["type"] == "string" and field_class.indexed: if not hasattr( field_class, "facet_for" ) and not field_class.field_type in ("ngram", "edge_ngram"): field_mapping["analyzer"] = getattr( field_class, "analyzer", self.DEFAULT_ANALYZER ) mapping.update({field_class.index_fieldname: field_mapping}) return content_field_name, mappingclass IKSearchEngine(ElasticsearchSearchEngine): backend = IKSearchBackend
11.实时更新索原理:采用信号
配置
# 在django配置文件中,添加索引值,文章更新的时候,就会自动更新索引值HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
RealtimeSignalProcessor源码如下:
class RealtimeSignalProcessor(BaseSignalProcessor): """ Allows for observing when saves/deletes fire & automatically updates the search engine appropriately. 当 检索对象出现保存或者删除的时候更新索引值。 """ def setup(self): # Naive (listen to all model saves). models.signals.post_save.connect(self.handle_save) models.signals.post_delete.connect(self.handle_delete) # Efficient would be going through all backends & collecting all models # being used, then hooking up signals only for those. def teardown(self): # Naive (listen to all model saves). models.signals.post_save.disconnect(self.handle_save) models.signals.post_delete.disconnect(self.handle_delete) # Efficient would be going through all backends & collecting all models # being used, then disconnecting signals only for those.
本文借鉴
Django haystack实现全文搜索 – -零 – 博客园 (cnblogs.com)
(9条消息) django-haystack全文检索详细教程_AC_hell的博客-CSDN博客
(9条消息) Django全文检索Haystack模块_NQ31的博客-CSDN博客_django haystack
(9条消息) django+drf_haystack+elasticsearch_骑台风走的博客-CSDN博客
(5条消息) Haystack 使用 Elasticsearch 建立索引时 修改为中文分词器_SevenBerry的博客-CSDN博客_elasticsearch 修改字段分词器
(5条消息) Elasticsearch中analyzer和search_analyzer的区别_chuixue24的博客-CSDN博客