python中elasticsearch_dsl模块的使用方法

前言

elasticsearch-dsl是基于elasticsearch-py封装实现的,提供了更简便的操作elasticsearch的方法。

安装:

install elasticsearch_dsl

连接elasticsearch

from elasticsearch_dsl import connections, Search
 
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
print(es)

还可以通过alias给连接设置别名,后续可以通过别名来引用该连接,默认别名为default。

from elasticsearch_dsl import connections, Search
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
print(es)
 
# 方式二:连接es
connections.create_connection(alias="my_new_connection", hosts=["127.0.0.1:9200"], timeout=20)

elasticsearch_dsl.Search

search对象代表整个搜索请求,包括:queries、filters、aggregations、sort、pagination、additional parameters、associated client。

API被设置为可链接的即和用.连续操作。search对象是不可变的,除了聚合,对对象的所有更改都将导致创建包含该更改的浅表副本。

当初始化Search对象时,传递elasticsearch客户端作为using的参数

示例代码1:

from elasticsearch_dsl import connections, Search
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# 方式二:连接es
connections.create_connection(alias="my_new_connection", hosts=["127.0.0.1:9200"], timeout=20)
 
# 不使用别名使用
res = Search(using=es).index("test_index").query()
# print(res)
for data in res:
    print(data.to_dict())
 
print("*" * 100)
 
# 使用别名后这样使用
res2 = Search(using="my_new_connection").index('test_index').query()
# print(e)
for data in res2:
    print(data.to_dict())

运行结果:

示例代码2:

from elasticsearch_dsl import connections, Search
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# 不使用别名使用
res = Search(using=es).index("test_index").query()
# print(res)
for data in res:
    print(data.to_dict())
 
print("*" * 100)
 
# 书写方式一:按条件查询数据
res2 = Search(using=es).index("test_index").query("match", name="张三")  # 查询时注意分词器的使用
for data in res2:
    print(data.to_dict())
 
print("*" * 100)
 
# 书写方式二:按条件查询数据
res3 = Search(using=es).index("test_index").query({"match": {"name": "张三"}})
for data in res3:
    print(data.to_dict())

运行结果:

在上述执行execute方法将请求发送给elasticsearch:
response = res.execute()

不需要执行execute()方法,迭代后可以通过to_dict()方法将Search对象序列化为一个dict对象,这样可以方便调试。

query方法

查询,参数可以是Q对象,也可以是query模块中的一些类,还可以是自已写上如何查询。

示例代码1:

from elasticsearch_dsl import connections, Search, Q
import time
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
res = Search(using=es, index="test_index").query().query()  # 当调用.query()方法多次时,内部会使用&操作符
print(res.to_dict())

运行结果:

filter方法

在过滤上下文中添加查询,可以使用filter()函数来使之变的简单。

示例代码1:

from elasticsearch_dsl import connections, Search, Q
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# res = Search(using=es).index("test_index").filter({"match": {"name": "北"}})
# res = Search(using=es).index("test_index").filter("terms", tags=["name", "id"])
res = Search(using=es).index("test_index").query("bool", filter=[
    Q("terms", tags=["name", "id"])])  # 上面代码在背后会产生一个bool查询,并将指定的条件查询放入到filter分支
print(res)
for data in res:
    print(data.to_dict())

示例代码2:

from elasticsearch_dsl import connections, Search, Q
import time
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# 范围查询
# res = Search(using=es, index="test_index").filter("range", timestamp={"gte": 0, "lt": time.time()}).query({"match": {"name": "北"}})
res = Search(using=es, index="test_index").filter("range", id={"gte": 1, "lte": 4}).query({"match": {"name": "北"}})
print(res)
for data in res:
    print(data.to_dict())
 
# 普通过滤
res2 = Search(using=es, index="test_index").filter("terms", id=["2", "4"]).execute()
print(res2)
for data in res2:
    print(data.to_dict())

运行结果:

示例代码3:

from elasticsearch_dsl import connections, Search, Q
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# 方式一
q = Q('range', age={"gte": 25, "lte": 27})
res = Search(using=es, index="account_info").query(q)
print(res.to_dict())
for data in res:
    print(data.to_dict())
 
print("*" * 100)
 
# 方式二
q2 = Q('range', **{"age": {"gte": 25, "lte": 27}})
res2 = Search(using=es, index="account_info").query(q2)
print(res2.to_dict())
for data in res2:
    print(data.to_dict())

运行结果:

index方法

        指定索引

usring方法

        指定哪个elasticsearch

elasticsearch_dsl.query

该库为所有的Elasticsearch查询类型都提供了类。以关键字参数传递所有的参数,最终会把参数序列化后传递给Elasticsearch,这意味着在原始查询和它对应的dsl之间有这一个清理的一对一的映射。

示例代码:

from elasticsearch_dsl import connections, Search, Q
from elasticsearch_dsl.query import MultiMatch, Match
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# 相对与{"multi_match": {"query": "ha", "fields": ["firstname", "lastname"]}}
m1 = MultiMatch(query="Ha", fields=["firstname", "lastname"])
res = Search(using=es, index="test_index").query(m1)
print(res)
for data in res:
    print(data.to_dict())
 
# 相当于{"match": {"firstname": {"query": "Hughes"}}}
m2 = Match(firstname={"query": "Hughes"})
res = Search(using=es, index="test_index").query(m2)
print(res)
for data in res:
    print(data.to_dict())

elasticsearch_dsl.Q

使用快捷方式Q通过命名参数或者原始dict类型数据来构建一个查询实例。Q的格式一般是Q("查询类型", 字段="xxx")或Q("查询类型", query="xxx", fields=["字段1", "字段2"])

示例代码1:

from elasticsearch_dsl import connections, Search, Q
from elasticsearch_dsl.query import MultiMatch, Match
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# q = Q("match", city="Summerfield")
q = Q("multi_match", query="Summerfield", fields=["city", "firstname"])
res = Search(using=es, index="test_index").query(q)
print(res)
for data in res:
    print(data.to_dict())

查询对象可以通过逻辑运算符组合起来:

Q("match", title="python") | Q("match", title="django")
# {"bool": {"should": [...]}}
 
Q("match", title="python") & Q("match", title="django")
# {"bool": {"must": [...]}}
 
~Q("match", title="python")
# {"bool": {"must_not": [...]}}

示例代码2:

from elasticsearch_dsl import connections, Search, Q
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# q = Q("multi_match", query="123.244.101.255", fields=["clientip", "timestamp"])
q = Q('match', name='张') | Q("match", name="北")
res = Search(using=es, index="test_index").query(q)
# print(res)
for data in res:
    print(data.to_dict(), data.name)
 
print("*" * 100)
 
q = Q('match', name='张') & Q("match", name="北")
res = Search(using=es, index="test_index").query(q)
# print(res)
for data in res:
    print(data.to_dict(), data.name)
 
print("*" * 100)
 
q = ~Q('match', name='张')
res = Search(using=es, index="test_index").query(q)
# print(res)
for data in res:
    print(data.to_dict(), data.name)

运行结果:

示例代码3:

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# constant_score内置属性
q = Q({"constant_score": {"filter": {"term": {"age": 25}}}})
 
res = s.query(q).execute()
for hit in res:
    print(hit.to_dict())
 
print("*" * 100)
 
q2 = Q("bool", must=[Q("match", address="山")], should=[Q("match", gender="男"), Q("match", emplyer="AAA")], minimum_should_match=1)
res2 = s.query(q2).execute()
 
for hit in res2:
    print(hit.to_dict())

运行结果:

嵌套类型

有时候需要引用一个在其他字段中的字段,例如多字段(title.keyword)或者在一个json文档中的address.city。为了方便,Q允许你使用双下划线‘__’代替关键词参数中的‘.’

示例代码:

from elasticsearch_dsl import connections, Search, Q
 
# 方式一:连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
# res = Search(using=es, index="test_index").query("match", address__city="北京")
res = Search(using=es, index="test_index").filter("term", address__city="北京")
# print(res)
for data in res:
    print(data.to_dict(), data.name)

查询

示例代码:

from elasticsearch_dsl import Search
from elasticsearch import Elasticsearch
 
# 连接es
es = Elasticsearch(hosts=["127.0.0.1:9200"], sniffer_timeout=60, timeout=30)
 
# 获取es中所有的索引
# 返回类型为字典,只返回索引名
index_name = es.cat.indices(format="json", h="index")
print(index_name)
 
# 查询多个索引
es_multi_index = Search(using=es, index=["personal_info_5000000", "grade", "test_index"])
print(es_multi_index.execute())
 
# 查询一个索引
es_one_index = Search(using=es, index="test_index")
print(es_one_index.execute())
 
print("*" * 100)
 
# 条件查询1
es_search1 = es_one_index.filter("range", id={"gte": 1, "lt": 5})
print(es_search1.execute())
 
# 条件查询2
es_search2 = es_one_index.filter("term", name="张")
print(es_search2.execute())
 
print("*" * 100)
 
# 结果转换为字典
es_search3 = es_search2.to_dict()
print(es_search3)
es_search4 = es_search2.execute().to_dict()
print(es_search4)

运行结果:

排序

示例代码:

from elasticsearch_dsl import connections, Search, A
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
res = s.query().sort('-age').execute()
# print(res)
for data in res:
    print(data.to_dict())

运行结果:

分页

要指定from、size

示例代码:

from elasticsearch_dsl import connections, Search, A
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
res = s.query()[2: 5].execute()  # {"from": 2, "size": 5}
# print(res)
for data in res:
    print(data.to_dict())

运行结果:

要访问匹配的所有文档,可以使用scan()函数,scan()函数使用scan、scroll elasticsearch API,需要注意的是这种情况下结果是不会被排序的。

示例代码:

from elasticsearch_dsl import connections, Search
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
res = s.query()
# print(res)
for hit in res.scan():
    print(hit.age, hit.address)

运行结果:

聚合

使用A快捷方式来定义一个聚合。为了实现聚合嵌套,你可以使用.bucket()、.metirc()以及.pipeline()方法。

bucket 即为分组,其中第一个参数是分组的名字,自己指定即可,第二个参数是方法,第三个是指定的field。

metric 也是同样,metric的方法有sum、avg、max、min等等,但是需要指出的是有两个方法可以一次性返回这些值,stats和extended_stats,后者还可以返回方差等值。

示例代码1:

from elasticsearch_dsl import connections, Search, A
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
a = A("terms", field="gender")
s.aggs.bucket("gender_terms", a)
res = s.execute()
# print(res)
for hit in res.aggregations.gender_terms:
    print(hit.to_dict())

运行结果:

示例代码2:

from elasticsearch_dsl import connections, Search, A
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
s.aggs.bucket("per_gender", "terms", field="gender")
s.aggs["per_gender"].metric("sum_age", "sum", field="age")
s.aggs["per_gender"].bucket("terms_balance", "terms", field="balance")
 
res = s.execute()
# print(res)
for hit in res.aggregations.per_gender:
    print(hit.to_dict())

运行结果:

 

示例代码3:

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
res = s.aggs.bucket("aaa", "terms", field="gender").metric("avg_age", "avg", field="age")
 
print(res.to_dict())

运行结果:

示例代码4:   【聚合,内置排序】

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
"""
{
	'terms': {
		'field': 'age',
		'order': {
			'_count': 'desc'
		}
	}
}
"""
s = Search(using=es, index="account_info")
res = s.aggs.bucket("agg_age", "terms", field="age", order={"_count": "desc"})
print(res.to_dict())
response = s.execute()
for hit in response.aggregations.agg_age:
    print(hit.to_dict())
 
"""
{
	'terms': {
		'field': 'age',
		'order': {
			'_count': 'asc'
		}
	},
	'aggs': {
		'avg_age': {
			'avg': {
				'field': 'age'
			}
		}
	}
}
"""
s2 = Search(using=es, index="account_info")
res2 = s2.aggs.bucket("agg_age", "terms", field="age", order={"_count": "asc"}).metric("avg_age", "avg", field="age")
print(res2.to_dict())
response = s2.execute()
for hit in response.aggregations.agg_age:
    print(hit.to_dict())

运行结果:

示例代码5:

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
"""
{
	'aggs': {
		'avg_age': {
			'avg': {
				'field': 'age'
			}
		}
	}
}
"""
s = Search(using=es, index="account_info").query("range", age={"gte": 28})
res = s.aggs.metric("avg_age", "avg", field="age")
print(res.to_dict())
response = s.execute()
print(response)
for hit in response:
    print(hit.to_dict())

运行结果:

高亮显示

示例代码:【目前似乎没有效果,待验证】

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="test_index")
res = s.highlight("id").execute().to_dict()
print(res)

运行结果:

source限制返回字段

示例代码:

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
res = s.query().execute()
for hit in res:
    print(hit.to_dict())
 
# 限制返回字段
s2 = Search(using=es, index="account_info")
res2 = s2.query().source(['account_number', 'address']).execute()
for hit in res2:
    print(hit.to_dict())

运行结果:

删除

调用Search对象上的delete方法而不是execute来实现删除匹配查询的文档

示例代码:

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="test_index")
res = s.query("match", name="张").delete()
print(res)

运行结果:

案例分析

创建索引:

from elasticsearch_dsl import Search
from elasticsearch import Elasticsearch
 
# 连接es
es = Elasticsearch(hosts=["127.0.0.1:9200"], sniffer_timeout=60, timeout=30)
 
body = {
    "mappings": {
        "properties": {
            "account_number": {
                "type": "integer"
            },
            "balance": {
                "type": "integer"
            },
            "firstname": {
                "type": "text"
            },
            "lastname": {
                "type": "text"
            },
            "age": {
                "type": "integer"
            },
            "gender": {
                "type": "keyword"
            },
            "address": {
                "type": "text"
            },
            "employer": {
                "type": "text"
            },
            "email": {
                "type": "text"
            },
            "province": {
                "type": "text"
            },
            "state": {
                "type": "text"
            }
        }
    }
}
 
# 创建 index
es.indices.create(index="account_info", body=body)

查看索引:

使用kibana批量生成数据:

POST account_info/_bulk
{"index": {"_index":"account_info"}}
{"account_number":1,"balance":20,"firstname":"三","lastname":"张","age":25,"gender":"男","address":"北京朝阳","employer":"AAA","email":"123@qq.com","province":"北京","state":"正常"}
{"index": {"_index":"account_info"}}
{"account_number":2,"balance":70,"firstname":"二","lastname":"张","age":26,"gender":"男","address":"北京海淀","employer":"AAA","email":"123@qq.com","province":"北京","state":"正常"}
{"index": {"_index":"account_info"}}
{"account_number":3,"balance":80,"firstname":"四","lastname":"张","age":27,"gender":"女","address":"辽宁朝阳","employer":"BBB","email":"123@qq.com","province":"辽宁","state":"正常"}
{"index": {"_index":"account_info"}}
{"account_number":4,"balance":60,"firstname":"五","lastname":"张","age":28,"gender":"男","address":"山东青岛","employer":"AAA","email":"123@qq.com","province":"山东","state":"正常"}
{"index": {"_index":"account_info"}}
{"account_number":5,"balance":40,"firstname":"六","lastname":"张","age":29,"gender":"女","address":"山东济南","employer":"AAA","email":"123@qq.com","province":"山东","state":"正常"}
{"index": {"_index":"account_info"}}
{"account_number":6,"balance":50,"firstname":"七","lastname":"张","age":30,"gender":"男","address":"河北唐山","employer":"BBB","email":"123@qq.com","province":"河北","state":"正常"}
{"index": {"_index":"account_info"}}
{"account_number":7,"balance":30,"firstname":"一","lastname":"张","age":31,"gender":"女","address":"河北石家庄","employer":"AAA","email":"123@qq.com","province":"河北","state":"正常"}

查看生成的数据:

根据条件查询:

1.查询balance在40~70的信息

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# 查询balance在40~70的信息
q = Q("range", balance={"gte": 40, "lte": 70})
 
res = s.query(q)
for data in res:
    print(data.to_dict())
 
print("共查到%d条数据" % res.count())

2.查询balance在40~70的男性信息

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# 查询balance在40~70的信息
q1 = Q("range", balance={"gte": 40, "lte": 70})
# 男性
q2 = Q("term", gender="男")
 
# and
q = q1 & q2
 
res = s.query(q)
for data in res:
    print(data.to_dict())
 
print("共查到%d条数据" % res.count())

3.省份为北京、25或30岁的男性信息

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# 方式一:
# 省份为北京
q1 = Q("match", province="北京")
# 25或30岁的男性信息
q2 = Q("bool", must=[Q("terms", age=[25, 30]), Q("term", gender="男")])
 
# and
q = q1 & q2
 
res = s.query(q)
for data in res:
    print(data.to_dict())
 
print("共查到%d条数据" % res.count())
 
print("*" * 100)
 
# 方式二
# 省份为北京
q1 = Q("match", province="北京")
# 25或30岁的信息
# q2 = Q("bool", must=[Q("terms", age=[25, 30]), Q("term", gender="男")])
q2 = Q("term", age=25) | Q("term", age=30)
# 男性
q3 = Q("term", gender="男")
 
res = s.query(q1).query(q2).query(q3)  # 多次query就是& ==> and 操作
for data in res:
    print(data.to_dict())
 
print("共查到%d条数据" % res.count())

4.地址中有“山”字,年龄不在25~28岁的女性信息

from elasticsearch_dsl import connections, Search, Q
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# 地址中有“山”字且为女性
q1 = Q("match", address="山") & Q("match", gender="女")
# 年龄在25~28岁
q2 = ~Q("range", age={"gte": 25, "lte": 28})
 
# 使用filter过滤
# query和filter的前后关系都行
res = s.filter(q2).query(q1)
for data in res:
    print(data.to_dict())
 
print("共查到%d条数据" % res.count())

5.根据年龄进行聚合,然后计算每个年龄的评价balance数值

示例代码:

from elasticsearch_dsl import connections, Search, A
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# 先用年龄聚合,然后拿到返平均数
# size指定最大返回多少条数据,默认10条
# 实质上account的数据中,age分组没有100个这么多
q = A("terms", field="age", size=100).metric("age_per_balance", "avg", field="balance")
 
s.aggs.bucket("res", q)
 
# 执行并拿到返回值
response = s.execute()
# res是bucket指定的名字
# response.aggregations.to_dict是一个{'key': 25, 'doc_count': 1, 'age_per_balance': {'value': 20.0}}的数据,和用restful查询的一样
 
for data in response.aggregations.res:
    print(data.to_dict())

运行结果:

6.根据年龄聚合,求25~28岁不同性别的balance值。

示例代码:

from elasticsearch_dsl import connections, Search, A
 
# 连接es
es = connections.create_connection(hosts=["127.0.0.1:9200"], timeout=20)
# print(es)
 
s = Search(using=es, index="account_info")
 
# 这次就用这种方法
# range 要注意指定ranges参数和from to
a1 = A("range", field="age", ranges={"from": 25, "to": 28})
a2 = A("terms", field="gender")
a3 = A("avg", field="balance")
 
s.aggs.bucket("res", a1).bucket("gender_group", a2).metric("balance_avg", a3)
 
# 执行并拿到返回值
response = s.execute()
# res是bucket指定的名字
 
for data in response.aggregations.res:
    print(data.to_dict())

运行结果: 【注意:不包含年龄28的值】

总结:

假如是数组,如:bool的must、terms,那么就要字段=[ ]假如是字典,如:range,那么就要字段={xxx: yyy, .... }假如是单值,如:term、match,那么就要字段=值假如查的是多个字段,如:multi_mathc,那么就要加上query="要查的值", fields=["字段1", "字段2", ...]然后各个条件的逻辑关系,可以通过多次query和filter或直接用Q("bool", must=[Q...], should=[Q...])再加上& | ~表示
作者:IT之一小佬 原文地址:https://blog.csdn.net/weixin_44799217/article/details/126925244

%s 个评论

要回复文章请先登录注册