Python quick start

At the end of this guide, you will have created a simple Python Hello, World! program that connects to the Memgraph database and executes simple queries.

Prerequisites

To follow this guide, you will need:

• A running Memgraph instance. If you need to set up Memgraph, take a look at the Installation guide.
• The GQLAlchemy client. A Memgraph OGM (Object Graph Mapper) for the Python programming language.
• A basic understanding of graph databases and the property graph model.

Basic setup

We'll be using a Python program to demonstrate how to connect to a running Memgraph database instance.

Let's jump in and connect a simple program to Memgraph.

1. Create a new directory for your program, for example, /memgraph_python and position yourself in it.

2. Create a new Python script and name it program.py . Add the following code to it:

from gqlalchemy import Memgraph

# Make a connection to the database
memgraph = Memgraph(host='127.0.0.1', port=7687)

# Delete all nodes and relationships
query = "MATCH (n) DETACH DELETE n"

# Execute the query
memgraph.execute(query)

# Create a node with the label FirstNode and message property with the value "Hello, World!"
query = """CREATE (n:FirstNode)
           SET n.message = '{message}'
           RETURN 'Node '  + id(n) + ': ' + n.message AS result""".format(message="Hello, World!")

# Execute the query
results = memgraph.execute_and_fetch(query)

# Print the first member
print(list(results)[0]['result'])

Note for Docker users

If the program fails to connect to a Memgraph instance that was started with Docker, you may need to use a different IP address (not the default localhost / 127.0.0.1 ) to connect to the instance.

You can find the CONTAINER_ID with docker ps and use it in the following command to retrieve the address:

docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' CONTAINER_ID

3. Now, you can run the application with the following command:

python ./program.py

You should see an output similar to the following:

Node 1: Hello, World!

Where to next?

For real-world examples of how to use Memgraph, we suggest you take a look at the Tutorials page. You can also browse through the How-to guides section to get an overview of all the functionalities Memgraph offers.