Neo4j Python Driver 4.1

The Official Neo4j Driver for Python.

Neo4j versions supported:

  • Neo4j 4.1

  • Neo4j 4.0

  • Neo4j 3.5

Python versions supported:

  • Python 3.8

  • Python 3.7

  • Python 3.6

  • Python 3.5

Note

The Python Driver 1.7 supports older versions of python, Neo4j 4.1 will work in fallback mode with that driver.

Installation

To install the latest stable release, use:

python -m pip install neo4j

To install the latest pre-release, use:

python -m pip install --pre neo4j

Note

It is always recommended to install python packages for user space in a virtual environment.

Virtual Environment

To create a virtual environment named sandbox, use:

python -m venv sandbox

To activate the virtual environment named sandbox, use:

source sandbox/bin/activate

To deactivate the current active virtual environment, use:

deactivate

Quick Example

Creating nodes.

from neo4j import GraphDatabase

uri = "neo4j://localhost:7687"
driver = GraphDatabase.driver(uri, auth=("neo4j", "password"))

def create_friend_of(tx, name, friend):
    tx.run("CREATE (a:Person)-[:KNOWS]->(f:Person {name: $friend}) "
           "WHERE a.name = $name "
           "RETURN f.name AS friend", name=name, friend=friend)

with driver.session() as session:
    session.write_transaction(create_friend_of, "Alice", "Bob")

with driver.session() as session:
    session.write_transaction(create_friend_of, "Alice", "Carl")

driver.close()

Finding nodes.

from neo4j import GraphDatabase

uri = "neo4j://localhost:7687"
driver = GraphDatabase.driver(uri, auth=("neo4j", "password"))

def get_friends_of(tx, name):
    friends = []
    result = tx.run("MATCH (a:Person)-[:KNOWS]->(f) "
                         "WHERE a.name = $name "
                         "RETURN f.name AS friend", name=name):
    for record in result:
        friends.append(record["friend"])
    return friends

with driver.session() as session:
    friends = session.read_transaction(get_friends_of, "Alice")
    for friend in friends:
        print(friend)

driver.close()

Example Application

import logging
from neo4j import GraphDatabase
from neo4j.exceptions import ServiceUnavailable

class App:

    def __init__(self, uri, user, password):
        self.driver = GraphDatabase.driver(uri, auth=(user, password))

    def close(self):
        # Don't forget to close the driver connection when you are finished with it
        self.driver.close()

    def create_friendship(self, person1_name, person2_name):
        with self.driver.session() as session:
            # Write transactions allow the driver to handle retries and transient errors
            result = session.write_transaction(
                self._create_and_return_friendship, person1_name, person2_name)
            for record in result:
                print("Created friendship between: {p1}, {p2}".format(
                    p1=record['p1'], p2=record['p2']))

    @staticmethod
    def _create_and_return_friendship(tx, person1_name, person2_name):

        # To learn more about the Cypher syntax,
        # see https://neo4j.com/docs/cypher-manual/current/

        # The Reference Card is also a good resource for keywords,
        # see https://neo4j.com/docs/cypher-refcard/current/

        query = (
            "CREATE (p1:Person { name: $person1_name }) "
            "CREATE (p2:Person { name: $person2_name }) "
            "CREATE (p1)-[:KNOWS]->(p2) "
            "RETURN p1, p2"
        )
        result = tx.run(query, person1_name=person1_name, person2_name=person2_name)
        try:
            return [{"p1": record["p1"]["name"], "p2": record["p2"]["name"]}
                    for record in result]
        # Capture any errors along with the query and data for traceability
        except ServiceUnavailable as exception:
            logging.error("{query} raised an error: \n {exception}".format(
                query=query, exception=exception))
            raise

    def find_person(self, person_name):
        with self.driver.session() as session:
            result = session.read_transaction(self._find_and_return_person, person_name)
            for record in result:
                print("Found person: {record}".format(record=record))

    @staticmethod
    def _find_and_return_person(tx, person_name):
        query = (
            "MATCH (p:Person) "
            "WHERE p.name = $person_name "
            "RETURN p.name AS name"
        )
        result = tx.run(query, person_name=person_name)
        return [record["name"] for record in result]

if __name__ == "__main__":
    # See https://neo4j.com/developer/aura-connect-driver/ for Aura specific connection URL.
    scheme = "neo4j"  # Connecting to Aura, use the "neo4j+s" URI scheme
    host_name = "example.com"
    port = 7687
    url = "{scheme}://{host_name}:{port}".format(scheme=scheme, host_name=host_name, port=port)
    user = "<Username for Neo4j database>"
    password = "<Password for Neo4j database>"
    app = App(url, user, password)
    app.create_friendship("Alice", "David")
    app.find_person("Alice")
    app.close()