Python读写图数据库Neo4j

     安装好图数据库Neo4j和相应的Python库neo4j-driver后（ http://blog.csdn.net/sweeper_freedoman/article/details/70189153 ），就正式开始读写Neo4j了。

# !/usr/bin/python# -*- coding: utf-8 -*-"""create_author : 蛙鳜鸡鹳狸猿create_time   : 2017-04-18program       : *_* Read and Write Neo4j *_*"""from neo4j.v1 import GraphDatabaseclass Neo4jHandler:    """    Handler of graph database Neo4j reading and writing.    """    def __init__(self, driver):        """        Get Neo4j server driver.        :param driver: driver object            A driver object holds the detail of a Neo4j database including server URIs, credentials and other configuration, see            " http://neo4j.com/docs/api/python-driver/current/driver.html ".        """        self.driver = driver    def __repr__(self):        printer = 'o(>﹏<)o ......Neo4j old driver "{0}" carry me fly...... o(^o^)o'.format(self.driver)        return printer    def listreader(self, cypher, keys):        """        Read data from Neo4j in specified cypher.        Read and parse data straightly from cypher field result.        :param cypher: string            Valid query cypher statement.        :param keys: list            Cypher query columns to return.        :return: list            Each returned record constructs a list and stored in a big list, [[...], [...], ...].        """        with self.driver.session() as session:            with session.begin_transaction() as tx:                data = []                result = tx.run(cypher)                for record in result:                    rows = []                    for key in keys:                        rows.append(record[key])                    data.append(rows)                return data    def dictreader(self, cypher):        """        Read data from Neo4j in specified cypher.        The function depends on constructing dict method of dict(key = value) and any error may occur if the "key" is invalid to Python.        you can choose function dictreaderopted() below to read data by hand(via the args "keys").        :param cypher: string            Valid query cypher statement.        :return: list            Each returned record constructs a dict in "key : value" pairs and stored in a big list, [{...}, {...}, ...].        """        with self.driver.session() as session:            with session.begin_transaction() as tx:                data = []                for record in tx.run(cypher).records():                    item = {}                    for args in str(record).split('>')[0].split()[1:]:                        exec "item.update(dict({0}))".format(args)                    data.append(item)                return data    def dictreaderopted(self, cypher, keys=None):        """        Optimized function of dictreader().        Read and parse data straightly from cypher field result.        :param cypher: string            Valid query cypher statement.        :param keys: list, default : none(call dictreader())            Cypher query columns to return.        :return: list.            Each returned record constructs an dict in "key : value" pairs and stored in a list, [{...}, {...}, ...].        """        if not keys:            return self.dictreader(cypher)        else:            with self.driver.session() as session:                with session.begin_transaction() as tx:                    data = []                    result = tx.run(cypher)                    for record in result:                        item = {}                        for key in keys:                            item.update({key : record[key]})                        data.append(item)                    return data    def cypherexecuter(self, cypher):        """        Execute manipulation into Neo4j in specified cypher.        :param cypher: string            Valid handle cypher statement.        :return: none.        """        with self.driver.session() as session:            with session.begin_transaction() as tx:                tx.run(cypher)        session.close()# self testif __name__ == "__main__":    uri = "bolt://localhost:7687"    driver = GraphDatabase.driver(uri, auth=("neo4j", "520"))    MyNH = Neo4jHandler(driver)    print(MyNH)    cypher_exec = """                    CREATE (Neo:Crew {name:'Neo'}),                           (Morpheus:Crew {name: 'Morpheus'}),                           (Trinity:Crew {name: 'Trinity'}),                           (Cypher:Crew:Matrix {name: 'Cypher'}),                           (Smith:Matrix {name: 'Agent Smith'}),                           (Architect:Matrix {name:'The Architect'}),                           (Neo)-[:KNOWS]->(Morpheus),                           (Neo)-[:LOVES]->(Trinity),                           (Morpheus)-[:KNOWS]->(Trinity),                           (Morpheus)-[:KNOWS]->(Cypher),                           (Cypher)-[:KNOWS]->(Smith),                           (Smith)-[:CODED_BY]->(Architect)                  """  # "example cypher statement from http://console.neo4j.org/"    cypher_read = """                    MATCH (a) -[:KNOWS|LOVES]-> (b:Crew {name: 'Trinity'})                    RETURN a.name AS l, b.name AS r                  """    MyNH.cypherexecuter(cypher_exec)    print(MyNH.listreader(cypher_read, ['l', 'r']))    print(MyNH.dictreader(cypher_read))    print(MyNH.dictreaderopted(cypher_read, ['l']))