python与neo-4j交互(对py2neo包做的笔记)
- 2020 年 1 月 21 日
- 筆記
1.连接数据库(三种方式相等)
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graph_1 = Graph()graph_2 = Graph(host="localhost")graph_3 = Graph("http://localhost:7474/db/data") |
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2.事务操作 a)直接返回结果
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graph.data("MATCH (a:Person) RETURN a.name, a.born LIMIT 4") |
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b)以pandas格式返回结果
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DataFrame(graph.data("MATCH (a:Person) RETURN a.name, a.born LIMIT 4")) |
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事务操作样例
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from py2neo import Graph, Node, Relationshipg = Graph()tx = g.begin()a = Node("Person", name="Alice")tx.create(a)b = Node("Person", name="Bob")ab = Relationship(a, "KNOWS", b)tx.create(ab)tx.commit()g.exists(ab) |
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3.匹配关系 查找alice的所有朋友
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for rel in graph.match(start_node=alice,rel_type="FRIEND"): print(rel.end_node()['name']) |
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4.带参数查询
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from py2neo import Graphg = Graph()# evaluate()返回结果的第一个值g.run(""MATCH (a) WHERE a.email={x} RETURN a.name",x="[email protected]").evaluate()g.run(""MATCH (a) WHERE a.email={x} RETURN a.name",x="[email protected]").data() |
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5.NodeSelector使用,可以使用Cypher语言的where部分
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from py2neo import Graph,NodeSelectorgraph = Graph()selector = NodeSelector(graph)slected = selector.select("Person",name="Keanu Reeves")list(selected)selected = selector.select("Person").where("_.name =~ 'J.*'","1960 <= _.born < 1970")list(selected) |
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6.删除操作
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# 删除所有的graph.delete_all() |
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