In the Cypher Fundamentals course, we cover how to query Neo4j using a language called Cypher. To execute a Cypher statement against a Neo4j database you will use an object called a Driver.
The Driver object is a thread-safe, application-wide fixture from which all Neo4j interaction derives.
The Driver API is topology independent, so you can run the same code against a Neo4j cluster or a single DBMS.
To connect to and query Neo4j from within a Python application, you use the Neo4j Python Driver.
The Neo4j Python Driver is one of five officially supported drivers, the others are Java, JavaScript, .NET, and Go. There are also a wide range of Community Drivers available for other languages including PHP and Ruby.
You should create a single instance of the Driver in your application per Neo4j cluster or DBMS, which can then be shared across your application.
Installing the Driver
The Neo4j Python Driver is available through the pip management system and can be installed with the pip command.
pip install neo4jCreating a Driver Instance
Each driver instance will connect to one DBMS, or Neo4j cluster, depending on the value provided in the connection string.
The neo4j package exports a GraphDatabase object. This object provides a driver() function for creating a new driver instance.
The driver() function requires one mandatory parameter, a connection string for the Neo4j cluster or DBMS - for example neo4j://localhost:7687 or neo4j+s://dbhash.databases.neo4j.io:7687.
Additionally, you will also pass a named parameter auth to represent the Neo4j user credentials.
You can provide basic username/password authentication by passing the username and password as a tuple.
Here is an example for how to create a driver instance to connect to a Neo4j instance running on localhost on port 7687 with the username neo4j and password neo:
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-typescript/main/example/index.py[tag=import]
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-typescript/main/example/index.py[tag=driver,indent=0]The above example creates an unencrypted connection to the Neo4j server at localhost on the default port number of 7687.
The driver then attemps to authenticate against the server using a basic authentication with the username neo4j and password neo.
Verifying Connectivity
You can verify that the connection details used during driver instantiation are correct by calling the verifyConnectivity() function.
This function will raise a Neo4jException with a code property of Neo.ClientError.Security.Unauthorized if a connection could not be made.
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-typescript/main/example/index.py[tag=verifyConnectivity,indent=0]Check Your Understanding
1. Which of the following programming languages have officially supported drivers?
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✓ .NET
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✓ Go
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✓ Java
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✓ JavaScript
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✓ Python
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❏ PHP
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❏ Ruby
Hint
Five languages are officially supported by Neo4j.
Solution
The five supported languages are .NET, Go, Java, JavaScript and Python.
2. What name is the Neo4j Python Driver registered under in the Python Package Index?
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❏
GraphDatabase -
✓
neo4j -
❏
neo4j-driver -
❏
neo4j-python-driver
Hint
The package is registered under neo4j.
Solution
The package is registered under neo4j.
Lesson Summary
In this lesson, you learned about the Neo4j Python Driver and how it can be used to connect to Neo4j from within a Python application.
In the next lesson, we will take a closer look at the first argument in the GraphDatabase.driver() function, the connection string.