• django+django-haystack+Whoosh(后期切换引擎为Elasticsearch+ik)+Jieba+mysql


    1.前提准备

    环境介绍

    • haystack是django的开源搜索框架,该框架支持SolrElasticsearch, 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

    1. pip3 install django==2.2 -i https://pypi.douban.com/simple
    2. pip3 install whoosh -i https://pypi.douban.com/simple
    3. pip3 install django-haystack -i https://pypi.douban.com/simple
    4. pip3 install jieba -i https://pypi.douban.com/simple
    5. pip3 install pymysql -i https://pypi.douban.com/simple
    6. pip3 install elasticsearch==7.6.0 -i https://pypi.douban.com/simple/

    项目结构

    1. - Project
    2. - Project
    3. - settings.py
    4. - blog
    5. - models.py

    表结构

    models.py

    1. from django.db import models
    2. class UserInfo(models.Model):
    3. username = models.CharField(verbose_name='用户名', max_length=225)
    4. def __str__(self):
    5. return self.username
    6. class Tag(models.Model):
    7. name = models.CharField(verbose_name='标签名称', max_length=225)
    8. def __str__(self):
    9. return self.name
    10. class Article(models.Model):
    11. title = models.CharField(verbose_name='标题', max_length=225)
    12. content = models.CharField(verbose_name='内容', max_length=225)
    13. # 外键
    14. username = models.ForeignKey(verbose_name='用户', to='UserInfo', on_delete=models.DO_NOTHING)
    15. tag = models.ForeignKey(verbose_name='标签', to='Tag', on_delete=models.DO_NOTHING)
    16. def __str__(self):
    17. 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

    1. # 数据库配置
    2. DATABASES = {
    3. 'default': {
    4. 'ENGINE': 'django.db.backends.mysql',
    5. 'NAME': 'dj_ha',
    6. 'USER': 'root',
    7. 'PASSWORD': 'foobared',
    8. 'HOST': '106.14.42.253',
    9. 'PORT': '11111',
    10. }
    11. }
    12. # app
    13. INSTALLED_APPS = [
    14. 'haystack',
    15. ]
    16. # 本教程使用的是Whoosh,故配置如下
    17. HAYSTACK_CONNECTIONS = {
    18. 'default': {
    19. 'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine',
    20. 'PATH': os.path.join(os.path.dirname(__file__), 'whoosh_index'),
    21. },
    22. }
    23. # 自动更新索引
    24. HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'
    25. # 设置每页显示的数目,默认为20,可以自己修改
    26. 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

    1. from haystack import indexes
    2. from .models import Article
    3. # ArticleIndex:固定写法 表名Index
    4. class ArticleIndex(indexes.SearchIndex, indexes.Indexable):
    5. # 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
    6. # 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)
    7. text = indexes.CharField(document=True, use_template=True)
    8. # 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
    9. # title:写入引擎的字段名,model_attr='title':相对应的表模型字段名,
    10. title = indexes.CharField(model_attr='title')
    11. content = indexes.CharField(model_attr='content')
    12. username = indexes.CharField(model_attr='username')
    13. tag = indexes.CharField(model_attr='tag')
    14. def get_model(self):
    15. # 需要建立索引的模型
    16. return Article
    17. def index_queryset(self, using=None):
    18. """Used when the entire index for model is updated."""
    19. # 写入引擎的数据,必须返回queryset类型
    20. 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

    1. {{ object.title }}
    2. {{ object.content }}
    3. {{ 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)

    1. # urls.py
    2. from django.contrib import admin
    3. from django.urls import path, include, re_path
    4. urlpatterns = [
    5. path('admin/', admin.site.urls),
    6. # 配置的搜索路由,路由可以自定义,include('haystack.urls')固定
    7. re_path(r'^search/', include('haystack.urls')),
    8. ]

     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)

    1. from django.urls import path
    2. from haystack.views import SearchView
    3. urlpatterns = [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)

    1. <h2>Searchh2>
    2. <style>
    3. span.highlighted {
    4. color: red;
    5. }
    6. style>
    7. {% load highlight %}
    8. <form method="get" action=".">
    9. <table>
    10. {{ form.as_table }}
    11. {# {{ form.title.label }}#}
    12. <tr>
    13. <td>td>
    14. <td>
    15. <input type="submit" value="Search">
    16. td>
    17. tr>
    18. table>
    19. {% if query %}
    20. <h3>返回结果h3>
    21. {% for result in page.object_list %}
    22. <p>
    23. {# <a href="{{ result.object.get_absolute_url }}">{{ result.object.title }}a>#}
    24. <a href="{{ result.object.get_absolute_url }}">{% highlight result.object.title with query %}a>
    25. p>
    26. <span>
    27. {% highlight result.object.content with query %}
    28. {# {{ result.object.content }}#}
    29. span>
    30. {% empty %}
    31. <p>没有查询到结果!!!p>
    32. {% endfor %}
    33. {% if page.has_previous or page.has_next %}
    34. <div>
    35. {% if page.has_previous %}<a href="?q={{ query }}&page={{ page.previous_page_number }}">{% endif %}«
    36. Previous{% if page.has_previous %}a>{% endif %}
    37. |
    38. {% if page.has_next %}<a href="?q={{ query }}&page={{ page.next_page_number }}">{% endif %}Next »
    39. {% if page.has_next %}a>{% endif %}
    40. div>
    41. {% endif %}
    42. {% else %}
    43. {# Show some example queries to run, maybe query syntax, something else? #}
    44. {% endif %}
    45. form>

     后端返回数据介绍

    1. # print(context)
    2. """
    3. {
    4. 'query': '刘',
    5. 'form': <ModelSearchForm bound=True, valid=True, fields=(q;models)>,
    6. 'page': <Page 1 of 1>,
    7. 'paginator': <django.core.paginator.Paginator object at 0x0000017D7E0F3470>,
    8. 'suggestion': None}
    9. """
    10. # print(context.get('page').__dict__)
    11. """
    12. {
    13. 'object_list':
    14. [
    15. <SearchResult: blog.article (pk=6)>,
    16. <SearchResult: blog.article (pk=8)>,
    17. <SearchResult: blog.article (pk=1)>
    18. ],
    19. 'number': 1,
    20. 'paginator': <django.core.paginator.Paginator object at 0x00000257C11A65C0>
    21. }
    22. """

    前端返回数据介绍

    1. {% load highlight %}:高亮加载 内置的会省略搜到的内容,之前的内容
    2. {% load my_filters_and_tags %}:自定义高亮
    3. form.as_table:生成表格,里边会自动成成input标签
    4. query:查询的参数
    5. page.object_list:返回的查询一页数据
    6. result:数据对象集
    7. result.object:当前查询的数据对象
    8. page.has_previous or page.has_next:分页

    6. 高亮配置 

    1. # 7.高亮加载
    2. <style>
    3. span.highlighted {
    4. color: red;
    5. }
    6. style>
    7. # 1.使用默认值
    8. {% highlight result.summary with query %}
    9. # 案例
    10. <a href="{{ result.object.get_absolute_url }}">
    11. {% highlight result.object.title with query %}
    12. a>
    13. # 2.这里我们为 {{ result.summary }}里所有的 {{ query }} 指定了一个<div>div>标签,并且将class设置为highlight_me_please,这样就可以自己通过CSS为{{ query }}添加高亮效果了,怎么样,是不是很科学呢
    14. {% highlight result.summary with query html_tag "div" css_class "highlight_me_please" %}
    15. # 3.这里可以限制最终{{ result.summary }}被高亮处理后的长度
    16. {% highlight result.summary with query max_length 40 %}
    17. # 5.自定义使用(后面会介绍)
    18. # 5.4格式
    19. {% myhighlight <text_block> with <query> [css_class "class_name"] [html_tag "span"] [max_length 200] [start_head True] %}
    20. # 5.2使用一
    21. {% myhighlight result.object.content with query css_class "highlighted" html_tag "span" max_length 200 start_head True %}
    22. # 5.3自定义二
    23. {% 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

    1. # 重写SearchView,实现自定义内容
    2. # blog/search_views.py
    3. from haystack.views import SearchView
    4. # 导入模块
    5. from .models import *
    6. class MySeachView(SearchView):
    7. def extra_context(self): # 重载extra_context来添加额外的context内容
    8. context = super(MySeachView, self).extra_context()
    9. my_str = '111'
    10. context['my_str'] = my_str
    11. # print(context)
    12. return context

    修改路由

    1. from django.contrib import admin
    2. from django.urls import path, include, re_path
    3. from blog import search_views
    4. urlpatterns = [
    5. path('admin/', admin.site.urls),
    6. # 原生的
    7. # re_path(r'^search/', include('haystack.urls')),
    8. # 自己的
    9. re_path(r'^search/', search_views.MySeachView(), name='haystack_search'),
    10. ]

    前端使用 

    1. <div>
    2. 圆明园:{{ my_str }}
    3. div>

    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,

    1. <form method="get" action=".">
    2. <table>
    3. <tr>
    4. <th>
    5. <label for="id_q">Search:label>
    6. th>
    7. <td>
    8. <input type="search" name="q" value="不得不说" id="id_q">
    9. td>
    10. tr>
    11. <tr>
    12. <td>
    13. <input type="submit" value="Search">
    14. td>
    15. tr>
    16. table>
    17. form>

    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

    1. # encoding: utf-8
    2. from __future__ import absolute_import, division, print_function, unicode_literals
    3. from django import template
    4. from django.conf import settings
    5. from django.core.exceptions import ImproperlyConfigured
    6. from django.utils import six
    7. from haystack.utils import importlib
    8. register = template.Library()
    9. class HighlightNode(template.Node):
    10. def __init__(self, text_block, query, html_tag=None, css_class=None, max_length=None, start_head=None):
    11. self.text_block = template.Variable(text_block)
    12. self.query = template.Variable(query)
    13. self.html_tag = html_tag
    14. self.css_class = css_class
    15. self.max_length = max_length
    16. self.start_head = start_head
    17. if html_tag is not None:
    18. self.html_tag = template.Variable(html_tag)
    19. if css_class is not None:
    20. self.css_class = template.Variable(css_class)
    21. if max_length is not None:
    22. self.max_length = template.Variable(max_length)
    23. if start_head is not None:
    24. self.start_head = template.Variable(start_head)
    25. def render(self, context):
    26. text_block = self.text_block.resolve(context)
    27. query = self.query.resolve(context)
    28. kwargs = {}
    29. if self.html_tag is not None:
    30. kwargs['html_tag'] = self.html_tag.resolve(context)
    31. if self.css_class is not None:
    32. kwargs['css_class'] = self.css_class.resolve(context)
    33. if self.max_length is not None:
    34. kwargs['max_length'] = self.max_length.resolve(context)
    35. if self.start_head is not None:
    36. kwargs['start_head'] = self.start_head.resolve(context)
    37. # Handle a user-defined highlighting function.
    38. if hasattr(settings, 'HAYSTACK_CUSTOM_HIGHLIGHTER') and settings.HAYSTACK_CUSTOM_HIGHLIGHTER:
    39. # Do the import dance.
    40. try:
    41. path_bits = settings.HAYSTACK_CUSTOM_HIGHLIGHTER.split('.')
    42. highlighter_path, highlighter_classname = '.'.join(path_bits[:-1]), path_bits[-1]
    43. highlighter_module = importlib.import_module(highlighter_path)
    44. highlighter_class = getattr(highlighter_module, highlighter_classname)
    45. except (ImportError, AttributeError) as e:
    46. raise ImproperlyConfigured("The highlighter '%s' could not be imported: %s" % (settings.HAYSTACK_CUSTOM_HIGHLIGHTER, e))
    47. else:
    48. from .highlighting import Highlighter
    49. highlighter_class = Highlighter
    50. highlighter = highlighter_class(query, **kwargs)
    51. highlighted_text = highlighter.highlight(text_block)
    52. return highlighted_text
    53. @register.tag
    54. def myhighlight(parser, token):
    55. """
    56. Takes a block of text and highlights words from a provided query within that
    57. block of text. Optionally accepts arguments to provide the HTML tag to wrap
    58. highlighted word in, a CSS class to use with the tag and a maximum length of
    59. the blurb in characters.
    60. Syntax::
    61. {% highlight with [css_class "class_name"] [html_tag "span"] [max_length 200] %}
    62. Example::
    63. # Highlight summary with default behavior.
    64. {% highlight result.summary with request.query %}
    65. # Highlight summary but wrap highlighted words with a div and the
    66. # following CSS class.
    67. {% highlight result.summary with request.query html_tag "div" css_class "highlight_me_please" %}
    68. # Highlight summary but only show 40 characters.
    69. {% highlight result.summary with request.query max_length 40 %}
    70. """
    71. bits = token.split_contents()
    72. tag_name = bits[0]
    73. if not len(bits) % 2 == 0:
    74. raise template.TemplateSyntaxError(u"'%s' tag requires valid pairings arguments." % tag_name)
    75. text_block = bits[1]
    76. if len(bits) < 4:
    77. raise template.TemplateSyntaxError(u"'%s' tag requires an object and a query provided by 'with'." % tag_name)
    78. if bits[2] != 'with':
    79. raise template.TemplateSyntaxError(u"'%s' tag's second argument should be 'with'." % tag_name)
    80. query = bits[3]
    81. arg_bits = iter(bits[4:])
    82. kwargs = {}
    83. for bit in arg_bits:
    84. if bit == 'css_class':
    85. kwargs['css_class'] = six.next(arg_bits)
    86. if bit == 'html_tag':
    87. kwargs['html_tag'] = six.next(arg_bits)
    88. if bit == 'max_length':
    89. kwargs['max_length'] = six.next(arg_bits)
    90. if bit == 'start_head':
    91. kwargs['start_head'] = six.next(arg_bits)
    92. return HighlightNode(text_block, query, **kwargs)

    highlighting.py

    1. # encoding: utf-8
    2. from __future__ import absolute_import, division, print_function, unicode_literals
    3. from django.utils.html import strip_tags
    4. class Highlighter(object):
    5. #默认值
    6. css_class = 'highlighted'
    7. html_tag = 'span'
    8. max_length = 200
    9. start_head = False
    10. text_block = ''
    11. def __init__(self, query, **kwargs):
    12. self.query = query
    13. if 'max_length' in kwargs:
    14. self.max_length = int(kwargs['max_length'])
    15. if 'html_tag' in kwargs:
    16. self.html_tag = kwargs['html_tag']
    17. if 'css_class' in kwargs:
    18. self.css_class = kwargs['css_class']
    19. if 'start_head' in kwargs:
    20. self.start_head = kwargs['start_head']
    21. self.query_words = set([word.lower() for word in self.query.split() if not word.startswith('-')])
    22. def highlight(self, text_block):
    23. self.text_block = strip_tags(text_block)
    24. highlight_locations = self.find_highlightable_words()
    25. start_offset, end_offset = self.find_window(highlight_locations)
    26. return self.render_html(highlight_locations, start_offset, end_offset)
    27. def find_highlightable_words(self):
    28. # Use a set so we only do this once per unique word.
    29. word_positions = {}
    30. # Pre-compute the length.
    31. end_offset = len(self.text_block)
    32. lower_text_block = self.text_block.lower()
    33. for word in self.query_words:
    34. if not word in word_positions:
    35. word_positions[word] = []
    36. start_offset = 0
    37. while start_offset < end_offset:
    38. next_offset = lower_text_block.find(word, start_offset, end_offset)
    39. # If we get a -1 out of find, it wasn't found. Bomb out and
    40. # start the next word.
    41. if next_offset == -1:
    42. break
    43. word_positions[word].append(next_offset)
    44. start_offset = next_offset + len(word)
    45. return word_positions
    46. def find_window(self, highlight_locations):
    47. best_start = 0
    48. best_end = self.max_length
    49. # First, make sure we have words.
    50. if not len(highlight_locations):
    51. return (best_start, best_end)
    52. words_found = []
    53. # Next, make sure we found any words at all.
    54. for word, offset_list in highlight_locations.items():
    55. if len(offset_list):
    56. # Add all of the locations to the list.
    57. words_found.extend(offset_list)
    58. if not len(words_found):
    59. return (best_start, best_end)
    60. if len(words_found) == 1:
    61. return (words_found[0], words_found[0] + self.max_length)
    62. # Sort the list so it's in ascending order.
    63. words_found = sorted(words_found)
    64. # We now have a denormalized list of all positions were a word was
    65. # found. We'll iterate through and find the densest window we can by
    66. # counting the number of found offsets (-1 to fit in the window).
    67. highest_density = 0
    68. if words_found[:-1][0] > self.max_length:
    69. best_start = words_found[:-1][0]
    70. best_end = best_start + self.max_length
    71. for count, start in enumerate(words_found[:-1]):
    72. current_density = 1
    73. for end in words_found[count + 1:]:
    74. if end - start < self.max_length:
    75. current_density += 1
    76. else:
    77. current_density = 0
    78. # Only replace if we have a bigger (not equal density) so we
    79. # give deference to windows earlier in the document.
    80. if current_density > highest_density:
    81. best_start = start
    82. best_end = start + self.max_length
    83. highest_density = current_density
    84. return (best_start, best_end)
    85. def render_html(self, highlight_locations=None, start_offset=None, end_offset=None):
    86. # Start by chopping the block down to the proper window.
    87. #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
    88. text = self.text_block[start_offset:end_offset]
    89. # Invert highlight_locations to a location -> term list
    90. term_list = []
    91. for term, locations in highlight_locations.items():
    92. term_list += [(loc - start_offset, term) for loc in locations]
    93. loc_to_term = sorted(term_list)
    94. # Prepare the highlight template
    95. if self.css_class:
    96. hl_start = '<%s class="%s">' % (self.html_tag, self.css_class)
    97. else:
    98. hl_start = '<%s>' % (self.html_tag)
    99. hl_end = '' % self.html_tag
    100. # Copy the part from the start of the string to the first match,
    101. # and there replace the match with a highlighted version.
    102. #matched_so_far最终求得为text中最后一个匹配query的结尾
    103. highlighted_chunk = ""
    104. matched_so_far = 0
    105. prev = 0
    106. prev_str = ""
    107. for cur, cur_str in loc_to_term:
    108. # This can be in a different case than cur_str
    109. actual_term = text[cur:cur + len(cur_str)]
    110. # Handle incorrect highlight_locations by first checking for the term
    111. if actual_term.lower() == cur_str:
    112. if cur < prev + len(prev_str):
    113. continue
    114. #分别添上每个query+其后面的一部分(下一个query的前一个位置)
    115. highlighted_chunk += text[prev + len(prev_str):cur] + hl_start + actual_term + hl_end
    116. prev = cur
    117. prev_str = cur_str
    118. # Keep track of how far we've copied so far, for the last step
    119. matched_so_far = cur + len(actual_term)
    120. # Don't forget the chunk after the last term
    121. #加上最后一个匹配的query后面的部分
    122. highlighted_chunk += text[matched_so_far:]
    123. #如果不要开头not start_head才加点
    124. if start_offset > 0 and not self.start_head:
    125. highlighted_chunk = '...%s' % highlighted_chunk
    126. if end_offset < len(self.text_block):
    127. highlighted_chunk = '%s...' % highlighted_chunk
    128. #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
    129. if self.start_head:
    130. highlighted_chunk = self.text_block[:start_offset] + highlighted_chunk
    131. return highlighted_chunk

    前端使用

    1. <style>
    2. span.highlighted {
    3. color: red;
    4. }
    5. style>
    6. {% load my_filters_and_tags %}
    7. {% 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

     在这里插入图片描述

    复制到的路径:

    9.2 对whoosh_cn_backend.py做以下修改:

    1. 1、导入 ChineseAnalyze
    2. from jieba.analyse import ChineseAnalyzer
    3. 2、替换schema_fields[field_class.index_fieldname] = TEXT(下的analyzer
    4. analyzer=ChineseAnalyzer(),

     9.3 在django的配置文件中,修改搜索引擎

    1. HAYSTACK_CONNECTIONS = {
    2. 'default': {
    3. # 设置haystack的搜索引擎
    4. 'ENGINE': 'blog.whoosh_cn_backend.WhooshEngine',
    5. # 'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine',
    6. # 设置索引文件的位置
    7. 'PATH': os.path.join(BASE_DIR, 'whoosh_index'),
    8. }
    9. }

    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?spm=1001.2014.3001.5501

    10.2 使用ik重写es7.5引擎

    10.2.1 新建elasticsearch_ik_backend.py(在自己的app下)

    在 blog应用下新建名为 elasticsearch7_ik_backend.py 的文件,继承 Elasticsearch7SearchBackend(后端) 和 Elasticsearch7SearchEngine(搜索引擎) 并重写建立索引时的分词器设置

    1. from haystack.backends.elasticsearch7_backend import Elasticsearch7SearchBackend, Elasticsearch7SearchEngine
    2. """
    3. 分析器主要有两种情况会被使用:
    4. 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,
    5. 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
    6. 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
    7. 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
    8. 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
    9. """
    10. DEFAULT_FIELD_MAPPING = {
    11. "type": "text",
    12. "analyzer": "ik_max_word",
    13. # "analyzer": "ik_smart",
    14. "search_analyzer": "ik_smart"
    15. }
    16. class Elasticsearc7IkSearchBackend(Elasticsearch7SearchBackend):
    17. def __init__(self, *args, **kwargs):
    18. self.DEFAULT_SETTINGS['settings']['analysis']['analyzer']['ik_analyzer'] = {
    19. "type": "custom",
    20. "tokenizer": "ik_max_word",
    21. # "tokenizer": "ik_smart",
    22. }
    23. super(Elasticsearc7IkSearchBackend, self).__init__(*args, **kwargs)
    24. class Elasticsearch7IkSearchEngine(Elasticsearch7SearchEngine):
    25. backend = Elasticsearc7IkSearchBackend

     10.3 修改settings.py(切换成功)

    1. # es 7.x配置
    2. HAYSTACK_CONNECTIONS = {
    3. 'default': {
    4. # 'ENGINE': 'haystack.backends.elasticsearch7_backend.Elasticsearch7SearchEngine',
    5. 'ENGINE': 'blog.elasticsearch_ik_backend.Elasticsearch7IkSearchEngine',
    6. # 'URL': 'http://106.14.42.253:9200/',
    7. 'URL': 'http://106.14.42.253:9200/',
    8. # elasticsearch建立的索引库的名称,一般使用项目名作为索引库
    9. 'INDEX_NAME': 'elastic_new',
    10. },
    11. }

    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:

    1. DEFAULT_FIELD_MAPPING = {
    2. "type": "text",
    3. "analyzer": "ik_max_word",
    4. "search_analyzer": "ik_smart",
    5. }

    10.5.2 es6版本加入ik,重写引擎

    1. from haystack.backends.elasticsearch_backend import ElasticsearchSearchBackend
    2. from haystack.backends.elasticsearch_backend import ElasticsearchSearchEngine
    3. class IKSearchBackend(ElasticsearchSearchBackend):
    4. DEFAULT_ANALYZER = "ik_max_word" # 这里将 es 的 默认 analyzer 设置为 ik_max_word
    5. def __init__(self, connection_alias, **connection_options):
    6. super().__init__(connection_alias, **connection_options)
    7. def build_schema(self, fields):
    8. content_field_name, mapping = super(IKSearchBackend, self).build_schema(fields)
    9. for field_name, field_class in fields.items():
    10. field_mapping = mapping[field_class.index_fieldname]
    11. if field_mapping["type"] == "string" and field_class.indexed:
    12. if not hasattr(
    13. field_class, "facet_for"
    14. ) and not field_class.field_type in ("ngram", "edge_ngram"):
    15. field_mapping["analyzer"] = getattr(
    16. field_class, "analyzer", self.DEFAULT_ANALYZER
    17. )
    18. mapping.update({field_class.index_fieldname: field_mapping})
    19. return content_field_name, mapping
    20. class IKSearchEngine(ElasticsearchSearchEngine):
    21. backend = IKSearchBackend

    11.实时更新索原理:采用信号

    配置

    1. # 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
    2. HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'

    RealtimeSignalProcessor源码如下:

    1. class RealtimeSignalProcessor(BaseSignalProcessor):
    2. """
    3. Allows for observing when saves/deletes fire & automatically updates the
    4. search engine appropriately.
    5. 当 检索对象出现保存或者删除的时候更新索引值。
    6. """
    7. def setup(self):
    8. # Naive (listen to all model saves).
    9. models.signals.post_save.connect(self.handle_save)
    10. models.signals.post_delete.connect(self.handle_delete)
    11. # Efficient would be going through all backends & collecting all models
    12. # being used, then hooking up signals only for those.
    13. def teardown(self):
    14. # Naive (listen to all model saves).
    15. models.signals.post_save.disconnect(self.handle_save)
    16. models.signals.post_delete.disconnect(self.handle_delete)
    17. # Efficient would be going through all backends & collecting all models
    18. # 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

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  • 原文地址:https://blog.csdn.net/qq_52385631/article/details/126590931