搜索引擎elasticsearch，对接Django

￡神魔★判官ぃ 2021-10-29 10:50 326阅读 0赞

#### 提高Django的搜索性能 ####

#### elasticsearch部署在docker中 ####

至于elasticsearch的基础知识，就不多说，有丰富的文档，供君阅读。

#### 建立索引数据模型 ####

这里使用的是python中的elasticsearch\_dsl，比较友好。使用ik中文分词插件，来进行分词，中文搜索。数据模型，与django中的model相对应，这里只选用用于搜索的关键字，存入索引库。

class AuthorComment(InnerDoc):
        id = Text()
        name = Text()
      
    class Course(Document):
        id = Text()
        name = Text(analyzer="ik_smart", search_analyzer="ik_smart", fields={'name': Keyword()})
    
        class Index:
            name = 'course'
            settings = {
                "number_of_shards": 2,
            }

#### Django数据发生变化时，同步到elasticsearch ####

这里利用Django提供的信号机制实现同步，如果有其他需要，可以自己写相应的信号来处理。

@receiver(post_save, sender=ModelCourse)
    def post_save_course(sender, **kwargs):
        try:
            instance = kwargs.get('instance')
            created = kwargs.get('created')
            para = {
                'name': instance.name,
                'img': instance.img,
            }
            if not created:
                course = Course.get(id=instance.id)
                course.update(**para)
            else:
                para['id'] = instance.id
                para['meta'] = {'id': instance.id}
                course = Course(**para)
                course.save()
        except BaseException as e:
            logger.error(e)
            logger.error('{} 添加一对一索引失败'.format(kwargs))

#### 建立搜索模型 ####

这里仅仅使用name字段搜索

class CourseSearch(FacetedSearch):
        index = 'course'
        doc_types = Course
        fields = ['name', ]
    
        def search(self):
            s = super(CourseSearch, self).search()
            return s.filter('term', strike=False)

#### 建立序列化器 ####

class CourseSerializer(serializers.Serializer):
        id = serializers.CharField(read_only=True)
        name = serializers.CharField(read_only=True)
    
        class Meta:
            fields = '__all__'

#### 建立视图 ####

这里的分页模型，均是从Django rest frame库中摘抄，见谅，见谅

from rest_framework.response import Response
    from rest_framework import viewsets, status
    from rest_framework.decorators import action
    from rest_framework.settings import api_settings
    
    from .search import CourseSearch
    from .serializers import CourseSerializer
    
    
    class SearchViewSet(viewsets.ViewSet):
        pagination_class = api_settings.DEFAULT_PAGINATION_CLASS
    
        @property
        def paginator(self):
            """
            The paginator instance associated with the view, or `None`.
            """
            if not hasattr(self, '_paginator'):
                if self.pagination_class is None:
                    self._paginator = None
                else:
                    self._paginator = self.pagination_class()
            return self._paginator
    
        def paginate_queryset(self, queryset):
            """
            Return a single page of results, or `None` if pagination is disabled.
            """
            if self.paginator is None:
                return None
            return self.paginator.paginate_queryset(queryset, self.request, view=self)
    
        def get_paginated_response(self, data):
            """
            Return a paginated style `Response` object for the given output data.
            """
            assert self.paginator is not None
            return self.paginator.get_paginated_response(data)
    
        @staticmethod
        def get_result(data):
            data = data['_source']
            try:
                author = data['author']
                data['author'] = author[0]
            except KeyError:
                pass
            return data
           
        @action(methods=['get'], detail=False)
        def course(self, request):
            name = self.request.query_params.get('name', None)
            bs = CourseSearch(name)
            response = bs.execute()
            data = response.hits.hits[0:100]
            data = list(map(self.get_result, data))
            page = self.paginate_queryset(data)
            serializer = CourseSerializer(page, many=True)
            data = self.get_paginated_response(serializer.data)
            return Response({'message': '获取成功', 'status': status.HTTP_200_OK, 'data': data})